Is the camera obscura a new discovery, and who invented it?

The camera obscura has been used for over a thousand years; its origin predates even the invention of optics. The first

camera obscura was simply a small hole in one wall of a darkened room or tent. Light passing through the hole formed an

inverted (upside down) image of the outside scene on a white screen placed across the room from the hole. The image was

dim and fuzzy, but it did accurately show the scenery in full color along with the motion of birds, ocean waves and tree

branches swaying in the wind.

Artists were undoubtedly the first “users” of the camera obscura, as they soon realized that one could trace on the screen

the outlines of buildings, trees, shadows and animals. This rough sketch could later be filled in with color to achieve the

artist’s objectives while maintaining correct perspective and sizes for near and distant objects.

It seems awkward to view an unsharp and inverted image. Can these problems be solved?

Both difficulties were solved soon after the invention

of optics in the early 1600s. When a lens replaced the hole in the wall it produced across the room an image that was both

brighter and sharper. However, the scene was still upside down. That problem was solved by arranging the lens to look

vertically upward into a flat mirror held at about 45° to the optical axis. Now the image is projected down onto a horizontal

white table where the scene will appear right side up if the viewer stands with his back to the outside area of interest.

Early lenses were single pieces of glass that produced a greatly improved image but one that still suffered from color fringes

around bright objects an increasing unsharpness° toward the edge of the viewing table. A camera obscura today uses a lens

with two or more glass elements that reduce these problems.

Four hundred years ago, the flat mirror was simply a polished metal plate. About 1850, opticians learned how to apply a

shiny silver film to a polished flat piece of glass, thereby producing a flatter mirror of much higher reflectivity. Today, most

flat mirrors are made by evaporating a film of aluminum onto a polished glass plate. This technique makes a much more

durable reflecting surface.

How can I make a simple camera obscura?

Such a basic device is often called a pinhole camera. It is made by cutting a ½ inch hole in one end of a light-tight cardboard

box and placing a white paper viewing screen on the opposite side of the box. The imaging pinhole is made in a small piece

of aluminum foil that is taped in place over the ½ inch hole.

The pinhole is made in the foil with a needle to produce a clean, sharp hole with a diameter of about 1/100th of the distance

from the hole to the screen. For example, if that distance is 10 inches, the pinhole should be about 1/10th of an inch in

diameter. Larger pinholes make a brighter but fuzzier image, while because of optical effects, a smaller pinhole also yields a

less sharp image.

The image on the white screen may be viewed by mounting the white screen over the hole cut in the side of the box. In this

case you view the inverted image through the backside of the white screen. Another arrangement uses a small hole cut in

the side of the box that is carefully shielded to keep out stray light yet allow the viewer to see the screen.

How can I make a brighter and sharper image than I get with a pinhole camera?

A better image is made by replacing the pinhole with a lens whose focal length is equal to the distance from the lens to the

viewing screen. The diameter of the lens might be ½ to 1 inch for a focal length of 10 inches. In a basic instrument this can

be a simple lens made of one lens element. Such lenses are available from the Edmund Optics Company

(www.edmundoptics.com).

Remember, both the pinhole and the lens produce an inverted image.

The pinhole camera is nice, but how can I make an imagethat shows more detail and appears right side up?

To achieve these improvements you must make a much bigger camera obscura in which the viewer sits inside the

instrument. Such a device uses a larger lens of longer focal length and also includes a flat mirror mounted above the lens.

The viewers now sit or stand inside the darkened room to see the image on a horizontal white table. Those viewers with

their back to the scene of interest will see a right side up image.

The smallest such instrument suitable for a single viewer might use a lens of 40 or 50-inch focal length. This device would

display details in the scene 4 or 5 times larger than produced by the 10-inch instrument described above. Larger lenses with

even longer focal length can reveal surprising features of very distant objects. For instance, a lens of 100 inches focal length

will show an image of the full moon that is about 1 inch in diameter. Such a view is like looking at the scene with a 10 power

binocular. The largest camera obscuras today use lenses of 12 to 14 inches diameter and produce focal lengths of 250 to

350 inches.

Large instruments are usually equipped with electric motors to carefully rotate the flat mirror about the vertical axis (azimuth)

and to tilt the mirror to shift the view upwards or downwards (altitude). Many camera obscuras also provide means to move

the lens vertically over several inches to focus the instrument on near or distant objects.

As the focal length of the lens is increased, the lens diameter must also be made larger in order to maintain adequate image

brightness. The ratio of lens focal length to diameter is called the speed or f/number of the lens; this ratio determines the

brightness of the scene on the table. This brightness is proportional to the square of the f/number. For example, the image

produced by an f/8 lens is four times brighter than that made by an f/16 lens. Most camera obscuras use lenses of f/15 to

f/30. Note that the apparent image brightness is strongly affected by stray light; the viewing room must be as near to total

darkness as possible.

Can I expect to view astronomical objects throughthe camera obscura?

Most camera obscuras are arranged to view the surrounding landscape of buildings, mountains, a coastline or a harbor

scene. These views occasionally will include a dramatic sunset or moonrise and indeed, such a scene can be especially

dramatic. Observers must use great care in looking toward the sun, as even a reddened sun near the horizon can easily

cause serious eye damage or blindness if viewed directly. The solar image on the view table may be dazzling but it will not

cause permanent eye damage.

The instrument can be specially designed to see the moon and bright planets even when 30° or 40° above the horizon. Such

a camera obscura must include a flat mirror that is significantly larger than normal. A conventional camera obscura uses a

flat mirror that is an inch or two wider than the lens diameter and also about 1.5 times longer than its width. The difference

between length and width is cause by the need to place the mirror at 45° to the lens optical axis. For example, a lens of 6-

inch diameter would require a flat mirror of about 7x10 inches.

If the camera obscura is to view objects higher in the sky it must use a flat mirror of the standard width but with up to twice

the usual length. Such a flat will be much more expensive than a normal mirror.

 

The Sky in a RoomGiorgio Carboni, May 1996

English version revised by Ed Vogel

 

CONTENTS

IntroductionThe main component: the converging lensLens on a windowLens on a wooden boardLens on a roll shutterConclusion

INTRODUCTION

This time, we will deal with an optical experiment easy to do, but which, in spite of its simplicity, is able to give you a continuous marvel. What you have to do is simply mount a lens on the bedroom window. In this way, when you wake up in the morning, you will admire the outside scene projected on a wall of your bedroom (figure 1).

If your window is turned to East, you will be able to enjoy the spectacle of dawn and the sunrise. This show changes every day, according to the seasons and the weather conditions, and you will never become tired of observing it. During a storm, lighting will seem to fall in your room. If you live in a City, during the night, you will see car lights to chase each other; the building in front of your house, open one eye or the other; you will see street lamps far away. Some nights, if you have the window facing the favorable direction, you will see the Moon run among the clouds.

For centuries, people experienced the observation of the world behind closed windows. If a knot in the wood of which the window was made just fell, the image of the outside world was formed on the opposite wall. This image is formed because light travels in straight lines. Hence, the rays coming from every object, passing through a thin hole, will attain distinct points on the wall. Those which are coming from a lower point, passing through the hole, will reach a high position on the wall, and vice versa. For this reason, the images produced are inverted.

The optical principle on which this experiment is based is that of the lens which creates images. You can read how this lens works in the section "From Lenses to Optical Instruments" of this Gallery.

This experiment is suitable also to explain the concept of camera obscura and how man has gone from the camera obscura to the photographic camera. The camera obscura is simply a dark room, which can have dimension ranging from many meters to a few centimeters. With a simple hole in a window, an image of the external world will be formed

on the opposite wall. Usually, this image is faint. To increase its brightness, you should enlarge the hole. Unfortunately, in doing so, the image becomes more confused. In order to obtain a brighter and a clearer image at the end of the XVI century, G.B. Della Porta suggested the use of a lens. Many artists of the renaissance used this system to draft their views. This method was particularly useful in taking architectural scenes, with the correct perspective.

For long time, people looked for chemical compounds sensible to the light to the aim of allowing the light draw the images by itself. The photographic camera born as a consequence of the success in these attempts. In fact, the photographic camera can be considered a camera obscura with a film: a surface sensible to the light, able to record it.

THE MAIN COMPONENT: THE CONVERGING LENS

Now, let's to see how you can make the experiment of the camera obscura, which will allow you to enjoy having the sky in your room and, in some manner, your soul outside. Its main component is a converging lens with a focal length about equal to the distance between the lens and the wall where the image is formed. Usually, this value will be comprised between 4 and 5 meters. You can buy the lens at the optician's. A meniscus lens for eyeglass, and as cheap as possible, is good.

Unlike all the people in the optics field, the eyeglass industry is the only one that measures focal lengths as diopters. So, when you go to the optician to buy the lens for this experiment, he will ask you how much power, or diopters, you want it. This simple formula allows you to pass from the focal length to the diopters:

D = 1/FL

where: D = dioptersFL = focal length of the lens (expressed in meters!)Besides,  people place the sign "+" before the power of a converging lens and the sign "-" before the power of a diverging lens. For this experiment you need a converging lens.

Let's make a couple of examples:- a converging lens of half a meter of focal length has a power of +2 diopters. In fact: D = 1/0,5 = +2

- a converging lens of 4 meter of focal length has a power of +0.25 diopters. In fact: D = 1/4 = +0,25

You cannot find in the market lenses of every value of focal length, but only of fixed values of 1/4 of diopter, so: +0.25  +0.5  +0.75  +1, etc. With difficulty you will be able to find in the market values such as +0.2 or +0.3 diopters which could be handy for you. In any case, ask to the optician for the lens of the theoretical power you need. It is his task to look for the one closer to the ideal measure. To this purpose, it is better to have a focal length shorter than the room width rather than longer. So, at least the objects close to the window could correctly focus on the wall. In terms of diopters, a slightly more powerful lens is better than a less powerful one.

Ask the optician to reduce the lens diameter so that it can settle down precisely in the bottom of a 24x36 film container, as shown in figure 2. This work is commonly performed by opticians to fit lenses into eyeglass frames, therefore do not be afraid to ask that to the optician. After this operation, make a case for your lens as that shown in figure 2. According to the type of window you have, you can mount the lens in different ways, some of which can be permanent, other temporary.

The mentioned below company produces lenses on demand. You can order one or more lenses with the diameter and focal length you need. As the price of one lens doesn't differ greatly from that of more, buy a few of them in order to have them in reserve.SILO SRL Via di Castelpulci 14/D - Badia a Settimo 50018 Scandicci (FI) silo@silo.it - http://www.silo.it  Lenses and other optical items.

LENS ON A WINDOW

Usually, in USA, houses have windows glasses sliding along the vertical direction. Outdoor light is attenuated by curtains and the room is not completely darkened. In order to make our experiment, it is necessary apply to these windows an opaque roll shutter which entirely halt the light. In fact, light must pass through the lens only. To this purpose, the shutter has to be fully opaque, and it must slide along two lateral guides. In commerce, you can find a shutter of this kind and you have only to saw it to the right width and then insert it in the window opening as shown in figure 3. If you do not find this type of shutter, you can buy an anti-mosquito roller web, and to replace the web with a black plasticized tissue, or a black plastic strong film.

After mounting the lens in its case, you have to insert it in the hole of the lens holder which you have to fasten to the window (fig. 3). When you will have inserted the shutter on the window opening, you must open a hole in the tissue in order to

allow light entering the room. Take care to close every other light source, otherwise your faint image will lose contrast.

This method is easy to perform, and allows you readily open the window to aerate the bedroom during the day.

 

LENS ON A WOODEN BOARD

In some other countries, the houses are constructed with heavy rolling shutter already fitted onto the windows. Usually, these shutters are made of wooden or plastic slats, which are hooked each other and slide along two lateral guides. When these shutters are completely down, never a light ray is entering the room. In this case, you can mount the lens in two manners: a temporary one and a permanentone.

The temporary solution involves mounting the case with the lens in a hole made in a wooden board. Place the board on the window-sill and pull down the shutter as you can see in figure 4. Take care of not let light to filter among the slats. As the board must be shorter than the windows width in order to be put in place, you have to close the remaining opening also.

LENS ON A ROLL SHUTTER

Permanent solution requires the authorization of your wife: a thing not easy to obtain! The question is to make a hole in a slat in order to insert the case with the lens in it. Figure 5 indicates how carry out this hole and fit the case in it. The plastic slats have two walls, one inside, the other outside. So, you have to make two coaxial holes of different diameter (fig. 5). You can easily make the internal hole with an annular drill. You can do the external hole with a circular path of little holes, removing the central part, and finishing with a half-round file. When you finish working the hole, place some glue and insert the lens case into the slat.

I have been successful in obtaining from my wife the authorization of making the hole in my shutter, and I have been very glad of this solution. From an aesthetical point of view, the work is not nasty to see and even my wife has not grumbled. The shutter works as usually, carrying and rolling the lens without any problem.

The solid corner of the light yielded by the lens is near 180°. This means that it will project the image on every wall of the room, floor and ceiling comprised. The only wall excluded is that of the window. Any way, the image will be distinct only on the wall opposite to the window. The other walls will send reflected light which will lower the contrast of the principal image. To get round this problem, at about 10 cm of distance from the lens, apply a mask with a rectangular hole. In my case, as the glass of my window is at this distance, I have been able to mount this mask directly on it. In doing so, I used an adhesive sheet of black plastic. This mask is useful also to stop the light which otherwise would arrive on your eyes when you are sleeping.

CONCLUSION

Every morning, when I wake up, I see in my bedroom the panorama of the external world. I know if there is the Sun, or if the sky is cloudy. Not only, but I watch also people walking in the park and trees swaying in the wind.

To have the external world inside your room, even only as an image, will improve remarkably the sleep quality because you feel yourself in some way out of the room and that will give you a great sense of freedom. As that fine song said: "The room has not more walls...". I think that this experiment has also a therapeutic capability for many people who are depressed or who have sleeping problems. However, pay attention when you are sleeping, because if the Moon disk should lie on your skin during a night of full Moon, you could be enraptured in a fantastic dream.

Building Information

'Amazing Camera Obscura' was born of an enthusiastic interest in Camera Obscura.

Over the last six years, showing and building Camera Obscura, we have gained experience that we can make available to all.

Our background in construction, specializing in traditional flintwork, means we have the skills necessary to build a Camera Obscura from the ground up. Alternatively it is possible to install optics into an existing building, be it a garden summer-house or a top floor room. We are also happy to work in

conjunction with designers and architects on new projects.

Site visits can be arranged via our contacts page.

Northampton Camera Obscura:

After hosting a talk on pinhole photography as part of the Pin:Whole exhibition at Essex University, Photographer Gina Glover saw our mobile booth Camera Obscura and contacted us with a view to turning an old summerhouse into a Camera Obscura.

Having visited the site to confirm the strength and suitability of the structure the design stage got underway. We decided to raise the viewpoint by mounting the optics in a tower on top of the summerhouse. Being a summerhouse it was endowed with a large number of windows, which we would deal with by means of wooden

shutters.

Once the designs were agreed upon we contacted our optics supplier to have them start making the lens to our requirements. Meanwhile we began to build the tower, turning gear and the viewing table in our Sussex workshop.

During the week preceding Easter we travelled up to Northamptonshire and began to convert the summerhouse. We started by strengthening the structure internally to accept the weight of the new tower. We then proceeded to cut a hole in the roof over which we put the tower. Once in position the turning gear and optics were installed. The Camera Obscura was not useable at this stage because of the enormous amount of light flooding in through the windows so we set about making the shutters. The viewing table - a semi-spherical dish - was given vertical movement to enable it to focus equally well on things both near and far.

Gina Glover told us:

"As someone who makes pinhole photography I am interested in the special qualities of image that the device produces. Everyone who has seen it finds the effect enchanting and say they have seen nothing like it. When you observe the images in the complete dark of the summerhouse, you feel like you are flying above the grounds of the house."

Making Your Own Camera Obscura

Simple camera obscura can be made in the following ways.

Room Camera Obscura

Open cardboard boxes out flat, and then use them to black out the windows in a room by pinning or taping them around the window frame. The room must be completely dark as any light coming in will ruin the image, use some tape to cover any small chinks of light. Next make a hole in one of the cardboard blackouts using a pencil, this will then project an image on to the opposite wall - hang up a white sheet if the wall is a dark colour. The image will be very dim, and it may take a few minutes before your eyes will adjust to the low light levels and the image becomes visible. A larger hole will let more light through, but will make for a more blurry image - experiment with the hole size until you reach a compromise between sharpness and brightness.

A large hole will make the image more blurry - that is unless you put a lens in the hole. A cheap lens can be purchased from any opticians with their own lab, prices vary from shop to shop.

Opticians measure the focal length of a lens in Dioptres. The lens must be a converging lens which opticians denote with a +.

For our purposes the focal length is the distance between the hole and the wall. If the wall is 2m away then the dioptre value will be 1 divided by the distance 2m which is ½ or +0.5 Dioptres. For 4m it will be 1 divided by 4m which is ¼ or +0.25 Dioptres.Cut a hole of a suitable size for the lens and fix it in place with tape. This will give you a brighter image.

Tube Camera Obscura

You Will Need:

Templates - printed onto light card (approx 220gsm) Download Template Forming Tube - around 70mm diameter cardboard tube Plastic Lens Tracing Paper Sticky Tape Scissors Stapler

Instructions

1. Roll Screen card around Forming Tube and tape up.

2. Trace the outer part of top Lens Disc onto the tracing paper and cut out.

3. Fix Tracing paper screen over one end of screen tube with tape.

4. Roll lens tube around screen tube and tape.

5. Cut out Lens Discs.

6. Sandwich lens between discs and staple together.

7. Fix assembled Lens Holder over the end of the lens tube.

8. Look at screen through tube, slide the Screen Tube in and out of Lens Tube to focus the image.

Lenses can be used but due to fixed focal length, camera size needs to relate directly to the focal length of the lens being used. Here is an opportunity for

experimentation.

1676

Johann Sturm (Germany) described first known use of a reflex mirror in a camera obscura.[14][15][16][17] The camera obscura

was known to Aristotle as an aid in observing solar eclipses, but its use as an artist's aid was first expounded

by Giambattista della Porta (Italy) in 1558.[18][19] The reflex mirror corrected the up-down image reversal that could make

using a non-SLR camera obscura disconcerting – but not the left-right reversal.

1685

Johann Zahn (Germany) developed a portable SLR camera obscura with focusable lens, adjustable aperture and

translucent viewing screen. These are all the core elements in a modern SLR photographic camera – except for an image

capture medium.[20][21][22] It would not be until 1826/27 before Joseph Nicéphore Niépce (France) made the first permanent

photograph using a bitumen photosensitized pewter plate in a non-SLR camera.[23][24] All advances in photographic

technology since then – mechanical, optical, chemical or electronic – have been convenience or quality improvements

only.

18th century

SLR camera obscuras popular as drawing aids. Artist can trace over the ground glass image to produce a true-life realistic

picture.[25][26][27][28]

[edit]19th century

1861

Thomas Sutton (UK) received first patent for SLR photographic camera. An unknown number made but very few; no

known production model; no known surviving examples. The manually levered reflex mirror also served as the camera's

shutter. Used glass plates.[28][29][30]

1884

Calvin Rae Smith Monocular Duplex (USA): first known production SLR. Used glass plates (original model 3¼×4¼ inch,

later 4×5 inch); many were adapted to use Eastman sheet film. Large-format glass plate or sheet film SLRs were the

dominant SLR type until circa 1915. However, SLRs themselves were not commonplace until the 1930s.[28][30][31][32] The

Duplex's name was a reference to the SLR's one lens performing both viewing and imaging duties, in contrast to the two

separate viewing and imaging lenses of the twin lens cameras (first production 1882 [Marion Academy; UK]; not

necessarily twin-lens reflex[TLR] camera, invented 1880 [one-of-a-kind Whipple-Beck camera; UK]) popular in the 1880s

and 90s.[33]

1891

A. D. Loman Reflex Camera (Netherlands): first focal-plane shutter SLR. Had mirror rise synchronized with the release of

a roller blind shutter, with speeds from ½ to 1/250 second, internally mounted in front of the focal plane, instead of the

previously normal unsynchronized, external accessory in front of the lens.[34] An internal camera-mounted traveling-slit FP

shutter's main advantage over the competing interlensleaf shutter was the ability to use a very narrow slit to offer up to an

action stopping 1/1000 second shutter speed at a time when leaf shutters topped out at 1/250 sec. – although the

available contemporaneous ISO 1 to 3 equivalent speed emulsions limited the opportunities to use the high speeds.[35]

[edit]Early 20th century

1903

Folmer & Schwing Stereo Graflex (USA): first (and only) stereo SLR. Strictly speaking, the Stereo Graflex was not a

“single”-lens reflex camera, because, as a stereo camera, it had two imaging lenses. However, it had a reflex mirror and a

typical for the era leather “chimney”-hooded waist level finder, albeit with dual eyepiece magnifiers. It took 5×7 inch glass

dry plates.[36]

1907

Folmer & Schwing Graflex No. 1A (USA): first medium format roll film SLR. Took eight exposures of 2½×4½ inch frames

on 116 roll film. Had folding waist level finder and focal-plane shutter. A sister SLR camera, the Graflex No. 3A, was

released at about the same time. It took six 3¼×5½ inch "postcard" frames on 122 roll film.[37][38][39] Roll film (usually 120

type) SLRs became the dominant SLR type in 1930s. The various models of large and medium format Graflex SLRs

made beginning in 1898, and culminating in the 4×5 inch sheet film Graflex Super D of 1948, are the best and most

famous American-made SLRs, if only for the shortage of competition.[40][41] Graflex quit the camera business in 1973.[42]

[43] A-127 is the rarest and most valuable at 1254 dollars – 3400 dollars

1925

Ernemann (merged into Zeiss Ikon, 1926) Ermanox Reflex (Germany): first SLR with high speed lens (10.5 cm

f/1.8 or 85mm f/1.8 Ernostar[44]). Established SLR as viable photojournalist's available-light camera. Had folding waist

level finder and focal-plane shutter. Used 4.5×6 cm glass plates or sheet film; adaptable to roll film.[28][45]

[edit]1930s

1933

Ihagee VP Exakta (Germany): first 127 roll film SLR. Preliminary designs were on paper by June 1932. Took eight

exposures of 4×6.5 cm (1⅝×2½ inch) nominal frames (40×62 mm actual frames) on 127 "Vest Pocket" roll film,[46] and had

a folding waist level finder and focal-plane shutter. The 1935 version was the first camera with a built-in flash

synchronization socket (called Vacublitz)[47] to automatically synchronize the recently invented flashbulb (first marketed as

Vacublitz in 1929[48]) with its shutter. The VP also established the oblong body shape and handling soon to be standard in

35 mm SLRs except that Exakta SLRs had primarily left-handed controls and were more trapezoidal shaped than

rectangular.[49]

1934

Eichapfel Noviflex (Germany): first 2¼ square format, medium format roll film SLR.[28] Took twelve exposures of 6×6 cm

(2¼×2¼ inch) frames on 120 roll film. Also had a fixed lens and focal-plane shutter. The 1937 version had

interchangeable lenses.[50][51] The square frame format precluded the awkward manipulations needed to take a vertical

photograph with horizontal rectangular format SLRs having then standard waist-level viewfinders.[52][53][54] The Noviflex was

not commercially successful; it was the Franz Kochmann Reflex-Korelle (Germany) of 1935 that established the

popularity of the 2¼ square format SLR.[55][56]

1935

135 film, commonly called 35 mm film, introduced by Kodak (USA). Was (and is) 35 mm nominal width (1⅜ inch actual

width[57][58]), acetate base, double perforated film, pre-loaded into felt-lipped, daylight-loading cartridges ready-to-use for

still cameras. Originally intended for Kodak Retina, Zeiss Ikon Contax and E. Leitz Leica 35 mm rangefinder cameras.

Previously, bulk rolls of 35 mm motion picture film would need to be user cut and loaded, in complete darkness, into

camera specific cartridges or magazines.[59] The September 1936 release of Kodachrome (the first high speed [ISO 8

equivalent], realistic color film) in standardized 135 format (but not medium format roll film) spurred explosive growth in

the popularity of all types of miniature format 35 mm cameras.[60] The vast majority were not high-end SLRs or RFs, but

basic amateur RFs such as the nearly three million selling Argus C3 (USA) of 1939.[61][62] Originally, each US$3.50

(including processing) Kodachrome cartridge gave eighteen exposures[63] if the camera used the 24×36 mm frame size

(double the frame size of 35 mm cine cameras) established by the Multi-Speed Shutter Co. Simplex (USA) camera of

1914 and popularized by the E. Leitz Leica A (Germany) of 1925.[64] The 24×36 mm frame size did not become the

universal standard frame size until the early 1950s. Note that 135 film cameras using non-standard frame sizes, such as

24×18 mm or 24×24 mm, continued to be made into the early 1990s.[65][66] Panoramic 135 film cameras using extra-wide

aspect ratio frame sizes (up to 24×160 mm for the 360° revolving slit Globuscope [USA] of 1981[67][68]) were still available

in 2006.[69]

1936

Ihagee Kine Exakta (Germany): first production 35 mm SLR, first system SLR, first interchangeable lens camera with

bayonet lens mount.[70][71][72][73][74] This was exhibited at the Leipzig Spring Fair in March and was in production by April

1936. Had left-handed shutter release and rapid film wind thumb lever, folding waist level finder and 12 to 1/1000 second

focal-plane shutter. Well-integrated design with excellent interchangeable lenses and good accessory system. Fewer than

30,000 Kine Exaktas were made before World War 2 stopped production in 1940.[75] Production of improved models re-

started after the war and Exakta was the best known 35 mm SLR brand until 1959.[76]

1936

E. Leitz PLOOT (Germany): first reflex housing for 35 mm rangefinder cameras. For use with a Leica IIIa RF and the

Leitz 20 cm f/4.5 Telyt or 40 cm f/5 Telyt long focus lenses (all Germany).[77] Long focus (and telephoto) lenses have

very shallow depth of field and the short baseline rangefinders built into RF cameras cannot triangulate the subject

distance accurately enough for acceptably sharp focusing.[78][79]SLRs do not suffer from this problem, because they are

focused by directly assessing the sharpness of the lens image – the lens serves as its own rangefinder.[80] Reflex

housings converted RFs into very awkward SLRs[81] by inserting a reflex mirror and focusing screen between the lens and

camera. Some even had image reversing optics. They also solved the RF camera's parallax error problem in

macrophotography.[82] Eventually, real SLRs were recognized as the simpler solution and supplanted RFs in the 1960s.

The last reflex housing for a film camera, the Leica Visoflex III (West Germany; for Leica M4 series RFs), was

discontinued in 1984.[83]

1937

Gosudarstevennyi Optiko-Mekhanichesky Zavod (GOMZ) Sport (Спорт; Soviet Union): a 35 mm (not 135 type[84]) SLR

apparently prototyped in 1935. However, sources are uncertain or conflict upon the Sport's introduction date – a plurality

say 1937. If it was sold in 1935, it would be the first 35 mm SLR. In any event, the Sport was not widely available and had

no influence on later SLRs.[28][85][86][87][88][89]

[edit]1940s

1947

Gamma Duflex (Hungary): first instant return mirror SLR,[90] first metal focal-plane shutter SLR, first internal semi-

automatic lens diaphragm SLR. Also had a mirror "prism" viewfinder, an intermediate step to a solid pentaprism. Reflex

mirrors coupled to the shutter release had been spring actuated to rise automatically since the 19th century, but the

viewfinder would remain blacked-out until the mirror was manually cocked back down.[14] With an automatic, instant return

mirror, the viewfinder blackout time might be as short as ⅛th second. The semi-auto diaphragm closed the lens

diaphragm with shutter release, but it needed to be manually re-cocked open. The Duflex was very ambitious, but very

unreliable and Gamma's first and last production SLR.[91]

1948

Hasselblad 1600F (Sweden): first 2¼ medium format system SLR suitable for professional use. Took twelve exposures

of 2¼×2¼ inch (6×6 cm) nominal frames (56×56 mm actual frames) on 120 film. Had modular design accepting

interchangeable lenses, film magazines and folding waist level finder. The 1/1600 second corrugated stainless steel focal-

plane shutter was unreliable and was replaced by a slower but more reliable 1/1000 second focal-plane shutter in

the Hasselblad 1000F (Sweden) of 1952.[92][93][94][95]

1948

Alpa Prisma Reflex (Switzerland) had a pentaprism viewfinder in 1948, but its eyepiece was angled upward at 45°.[96]

1949

VEB Zeiss Ikon (Dresden) Contax S (East Germany): first pentaprism eyelevel viewing 35 mm SLR.[97][98][99][100][101][102][103]

[104] (The Italian Rectaflex Standard came very soon after.[105][106][107]) First M42 screw mount camera. (The East German

KW Praktica came out at about the same time.)[108] With earlier "waist level" SLR viewfinder systems (in which the

photographer looks downward at the reflex mirror's image on the focusing screen), moving subjects are seen to track

across the field-of-view in reverse direction of their actual motion, making action shooting counter-intuitive. A pentaprism

is an eight-sided (only five are of significance; the other three are cut off corners) chunk of glass silvered on three sides

that collects, redirects and re-reverses the light from the mirror with minimal light loss.[109][110] With a proper pentaprism, all

a photographer needs to do is hold the camera up to eyelevel and everything is there.[111][112] The pentaprism SLR had first

been proposed in the 19th century and was used in non-35 mm SLRs in the 1930s. Similar systems (or, in the 1990s, its

cheaper alternative, the pentamirror[113][114]) became so common in 35 mm SLRs by the late 1950s that it is the

characteristic pentaprism "head" atop the camera body that defines the type for most people.[115]

[edit]1950s

1950

Ihagee Exakta Varex (East Germany; called Exakta V in USA): first interchangeable viewfinder, first interchangeable

focusing screens, first viewfinder condenser lens SLR.[116][117] Original viewfinder selection was waist-level or pentaprism.

[118] For the next half-century, interchangeable viewfinder customization was the signal feature of fully professional level

SLRs, although they have not made the transition to digital SLRs.

1950

Angénieux 35mm f/2.5 Retrofocus Type R 1 (France): first retrofocus wide angle lens for 35 mm SLRs (for Exaktas).[119]

[120] Regular wide angle lenses (meaning short focal length lenses) need to be mounted close to the film. However, SLRs

require that lenses be mounted far enough in front of the film to provide space for the movement of the mirror — the

"mirror box." Therefore, the focal length of early 35 mm SLR lenses were no less than about 40 mm. This prompted the

development of wide view lenses with more complex retrofocus optical designs. These use very large negative front

elements to force back-focus distances long enough to ensure clearance.[121][122] Note, "retrofocus" was an Angénieux

trademark before losing exclusive status. The original generic term is "inverted telephoto." A telephoto lens (multiple

inventions, 1891[123]) has a front positive group and rear negative group;[124] retrofocus lenses have the negative group in

front and positive group to the rear.[125] The first inverted-telephoto imaging lens was the Taylor-Hobson 35mm f/2 (1931,

UK) developed to provide back-focus clearance for the beamsplitter prism used by the full-color via three

negative Technicolor motion picture process.[121] Retrofocus wide angle prime lenses reached fields of view as wide as

118° with the Nikkor 13mm f/5.6 (Japan) lens for Nikon 35 mm SLRs in 1975, but they are extremely large compared to

non-SLR short focal length lenses because of their gigantic negative elements.[126][127][128]

1951

Zenit (Soviet Union, Russia; Зенит): first Russian pentaprism eyelevel viewing 35 mm SLR.

1952

Asahiflex I (Japan): first Japanese 35 mm SLR. Had folding waist level finder and focal-plane shutter.[90][129][130][131][132]

[133] From 1952 to 1983, Asahi Optical (today called Pentax and owned by Hoya) manufactured cameras exclusively of

SLR type[134] and has made them in the greatest variety of formats of any modern camera company – from 110 to 6×7 film,

and today's digital.

1953

VEB Zeiss Ikon (Dresden) Contax E (East Germany): first built-in light meter SLR. Had an external selenium photoelectric

cell mounted behind a door on the pentaprism housing, above the lens. The meter was uncoupled – the photographer

would need to wait until the meter stabilized and manually set the shutter speed and lens aperture to match the indicated

exposure reading.[135] The first camera with a built-in meter (also uncoupled) was the Zeiss Ikon Contaflex (Germany)

35 mm twin-lens reflex (TLR) camera of 1935.[84][135][136][137]

1

9

5

3

Zeiss Ikon Contaflex I (West Germany): first leaf shutter 35 mm SLR. Had Synchro-Compur leaf shutter and fixed 45mm

f/2.8 Tessar lens.[138][139][140][141] For many years, reliable focal-plane shutters were very expensive and SLRs equipped with

Compur or Prontor leaf shutters were strong competitors.[142][143] As FP shutters improved, their faster available speeds

won out in the late 1960s and leaf shutter 35 mm SLRs disappeared around 1976.[144][145]

195

3

Metz/Kilfitt Mecaflex (West Germany): first (and only) square format 35 mm SLR. Took up to fifty exposures of 24×24 mm

frames on 135 film. A compact Prontor leaf shutter design with bayonet mount interchangeable lenses.[146][147][148] 135 film's

standard 24×36 mm frame size is inefficient.[149] Its 3:2 aspect ratio is too wide, recording only 59% of a required 43.3 mm

diameter lens image circle. This makes lenses for the format overly large for the image area. A square 24×24 mm frame

maximizes coverage at 64% of a smaller 33.9 mm image circle. The Mecaflex's designer, Heinz Kilfitt, also designed

theRobot (Germany) of 1934, the first 24×24 mm 35 mm (not 135 type) camera.[150] Both failed to disturb the entrenched

rectangular format and the 3:2 ratio still dominates digital SLRs. Olympus' Four Thirds System digital format of 2002 is the

latest attempt at a narrower, albeit not square, format.[151] Note that dual 24×24 mm frames on 135 film were used by the

non-SLR David White Stereo Realist (USA, 1947), leader of the 1950s stereo photography fad.[152]

1954

Asahiflex IIB (Japan; called Sears Tower 23 in USA): first SLR with reliable instant return mirror.[111][133][153][154][155][156][157]

1954

Praktina FX (East Germany): first available spring powered motor drive accessory for SLR, first breech-lock lens mount.

[158]

1954

Tokiwa Seiki Firstflex 35 (Japan): first interchangeable lens, leaf shutter 35 mm SLR. Otherwise a wholly forgettable

camera; cheaply made to low specifications and of poor quality, with waist level finder.[159]

1955

Miranda T (Japan): first Japanese pentaprism eyelevel viewing 35 mm SLR.[160][161][162] Note that the Tokiwa

Seiki Pentaflex (Japan), a modified Firstflex 35 (see above), had an eyelevel viewfinder four months before the Miranda,

but using a porroprism.[159] Orion Seiki (company renamed Miranda Camera in 1957) produced a versatile SLR system in

the 1960s, called by some "the poor man's Nikon," but was unable to keep up with the rapid electronic advancements of

the 1970s and went bankrupt in 1977.[163]

1955

Kilfitt 4 cm f/3.5 Makro-Kilar (West Germany/Liechtenstein): first close focusing "macro" lens for 35 mm SLRs (for

Exaktas and others). Version D focused from infinity to 1:1 ratio (life-size) at two inches; version E, to 1:2 ratio (half life-

size) at four inches.[164][165][166] Because SLRs do not suffer from parallax error, they are far superior for close-up

photography than cameras with other viewfinder systems.[82]Most SLR lens lines continue to include macro lenses

optimized for high magnification, although their focal lengths tend to be longer than the original Makro-Kilar to allow more

working distance. "Macro zoom" lenses began appearing in the 1970s, but traditionalists object to calling most of them

macro because they usually do not focus closer than 1:4 ratio with relatively poor image quality.[167][168]

1956

Zeiss Ikon Contaflex III (West Germany): first high-quality, interchangeable lens, leaf shutter 35 mm SLR. Was improved

Contaflex I (see above) with bayonet mounted front cell lenses.[169][170][171]

1957

Asahi Pentax (Japan; called Sears Tower 26 in USA[172]): first SLR with right-handed rapid-wind thumb lever, first fold-out

film rewind crank, first microprism focusing aid. First Asahi SLR with M42 screw mount. Established the "modern" control

layout of the 35 mm SLR. Well-integrated focal-plane shutter, instant return mirror and pentaprism design.[173][174][175]

1957

Hasselblad 500C (Sweden): replaced the Hasselblad 1600F/1000F's (see above) problematic focal-plane shutter with

reliable interlens Synchro-Compur leaf shutters and made the 2¼ medium format SLR the dominant professional studio

camera by the late 1950s. Well-integrated, durable and reliable design without instant return mirror, but with excellent

auto-diaphragm interchangeable lenses and large accessory system.[176][177][178]

1958

Zunow SLR (Japan): first internal auto-diaphragm (Zunow-matic Diaphragm System) 35 mm SLR and lenses. Well-

integrated focal-plane shutter, instant return mirror, pentaprism and auto-diaphragm design with excellent lenses and

good accessory system.[179] Stopping down (closing) the lens aperture (iris) to prepare for exposure transmits less light to

the mirror and the viewfinder may become very dim – perhaps even too dark to see the image. Auto-diaphragms coupled

to the shutter release that automatically stop down when the mirror swings up and reopen when the mirror comes down

provides almost continuous fully open aperture viewing. Auto-diaphragm lenses and instant return mirror, focal-plane

shutter SLRs require precise camera-to-lens linkage, but can choreograph the entire shutter-button release, close lens,

raise mirror, open shutter, close shutter, lower mirror, open lens exposure sequence[180] in as little as ⅛th second.

Originally, these were mechanical spring/gear/lever systems energized concurrent with manually winding the film, but

modern systems are electronically timed and operated by an electromagnet. The financially weak Zunow company was

unable to capitalize on its design; few examples of the camera (and much fewer of the wide and tele lenses for it) were

produced before the company switched back to lenses for other companies' cameras. Zunow went bankrupt in 1961.

[181] Note, the 1954 version of the Ihagee Exakta VX (East Germany) 35 mm SLR introduced an external auto-diaphragm

lens system using a spring-loaded shutter button plunger connection rod.[182][183]

1959

Zeiss Ikon Contarex (West Germany): first SLR with a built-in light meter coupled to a viewfinder exposure control

indicator – a galvanometer needle pointer. It had an external, circular selenium photoelectric cell mounted above the lens;

[184][185] earning it "Bullseye" (in USA) and "Cyclops" (in UK) nicknames.[186] For proper exposure, the photographer would

adjust the meter, which was also coupled to the shutter speed and lens aperture, until the needle was centered on a mark.

[187][188] (The Carl Braun Paxette Reflex [West Germany] leaf shutter SLR had an external top mounted, coupled light

meter needle system in 1958.[189]) The Contarex also had interchangeable film backs, a feature common with medium

format SLRs and used in a few 35 mm rangefinder cameras, but almost exclusive to Contarex/Contaflex series among

35 mm SLRs. Although Contarex SLRs and their Zeiss lenses were of extremely high quality, they were also extremely

expensive[190][191][192][193] and of idiosyncratic (even clumsy) handling.[194][195]

1959

Nikon F (Japan): first pro caliber 35 mm system SLR,[196][197][198][199][200] first electric motor drive accessory for SLR. (The

Japanese Nikon SP 35 mm rangefinder camera had the first electric motor drive for any camera type in 1957.[201][202]) Well-

integrated, durable and reliable focal-plane shutter, instant return mirror, pentaprism and auto-diaphragm design with

excellent interchangeable lenses and huge accessory system. Although the F was not technologically ground-breaking, it

sold 862,600 units[203] and made the 35 mm SLR the dominant professional miniature format camera (displacing the

35 mm RF) by the early 1960s.[204][205] The perfection of the optical and mechanical formulae of the interchangeable lens

SLR in the one-two punch of the Hasselblad 500C (see above) and Nikon F also ended the popularity of the medium

format twin-lens reflex (TLR) camera (typified by the Franke & Heidecke Rolleiflex/Rolleicord series [Germany, later

West Germany]) by the early 1960s.[206][207][208] The F's improved successor, the Nikon F2 (Japan) of 1971, is widely

regarded as the finest mechanically controlled 35 mm SLR camera ever made.[209]

1959

Voigtländer–Zoomar 1:2.8 f=36mm–82mm (USA/West Germany): first zoom lens for 35 mm still cameras.[210]

[211] Designed by Zoomar in USA and manufactured by Kilfitt in West Germany for Voigtländer. Originally mounted

for Voigtländer Bessamatic series (West Germany) 35 mm leaf shutter SLRs, but later available in Exakta and other

mounts.[212][213][214] Zoom lenses and SLR film cameras are perfect for each other, because an SLR always shows what the

lens is imaging during zooming, something difficult, if not impossible, to do with other optical viewfinder systems.[215][216]

[edit]1960s

1960

Konica F (Japan): first SLR with 1/2000 second and 1/125 second flash X-synchronization focal-plane shutter.[217][218]

[219] Modern focal-plane shutters are dual curtain traveling slit shutters.[220][221][222][223]They provide faster shutter speeds by

timing the second shutter curtain to close sooner after the first curtain opens and narrowing the slit "wiping" the exposure

on the film, instead of moving the curtains faster across film gate,[221][222][224][225] because they are too fragile to survive the

necessary accelerative shocks.[226] Long wipe times can cause cartoonish distortion of very fast moving objects instead of

truly freezing their motion.[227][228][229][230] (The use of leaning in illustration to give the impression of speed is a caricature of

the distortion caused by the slow wiping FP shutters of Graflex large format SLRs from the first half of the 20th century.

[231]) Unacceptable distortion (as well as difficulties in precisely timing very narrow slits[232]) had stalled traditional cloth

horizontal-travel FP shutters for 35 mm cameras at 1/1000 sec. and 1/60 sec. X-sync for decades. The F's Hi-

Synchro shutter[233] provided faster speeds by having its metal blades travel vertically along the minor axis of the

24×36 mm frame.[234][235] In 1982, the Nikon FM2 (Japan) reached 1/4000 sec. (and 1/200 sec. flash X-sync)[236] with a

vertical-travel FP shutter using honeycomb pattern etched titanium foil blades, stronger and lighter than plain stainless

steel. This allowed quicker shutter-curtain travel time (3.6 milliseconds, about half of earlier vertical, metal bladed

shutters) and thereby truly faster shutter speeds.[237] The Nikon FE2 (Japan), with an improved version of this shutter,

boosted X-sync speed to 1/250 sec. (3.3 ms curtain travel time) in 1983.[238] The fastest FP shutter ever used in a film

camera was the 1/12,000 sec. (1/300 sec. X-sync; 1.8 ms curtain travel time) duralumin and carbon fiber bladed one

introduced by the Minolta Maxxum 9xi (Japan) in 1992.[239][240]

1960

Royer Savoyflex Automatique (France): first autoexposure SLR. Had an unreliable mechanical shutter-priority

autoexposure system controlled by an external selenium light meter, Prontor leaf shutter and fixed 50mm f/2.8 Som-

Berthiot lens.[93][241][242][243] The first autoexposure still camera was the non-SLR Kodak Super Kodak Six-20 (USA) of 1938

with a mechanical system controlling both aperture and shutter speed via trapped-needle method coupled to external

selenium photoelectric cell.[244][245][246][247]

1960

Krasnogorsky Mekhanichesky Zavod (KMZ) Narciss (Soviet Union; Нарцисс): first subminiature SLR. Took 14×21 mm

frames on unperforated, specially spooled 16 mm film. Compact design with interchangeable lenses and removable

finder. Submini film format cameras (those using smaller than 135 film) have always been unpopular with serious

photographers because the very high level of enlargement needed to make even small 3½×5 inch prints from such tiny

negatives can magnify normally minor image limitations unless using the highest quality cameras, lenses, films and

techniques.[93][248][249][250]

1961

35 mm f/3.5 PC-Nikkor lens — the first perspective control lens for a 35 mm camera, permitting control of perspective in

architectural photography.

1962

Nikkorex Zoom 35 (Japan): first 35 mm SLR with fixed zoom lens (Zoom-Nikkor Auto 43–86mm f/3.5). Had non-

pentaprism, four mirror reflex viewfinder and leaf shutter.[111][251][252][253] Fixed lens SLRs have been an occasional

phenomenon bridging simpler viewfinder cameras and more ambitious interchangeable lens SLRs. Presently, they are off-

again with non-SLR electronic viewfinder (EVF) superzoom digital cameras occupying this market segment.[254][255]

1963

Topcon RE Super (Japan; called Super D in USA; name became Super D worldwide in 1972[256]): first SLR with through-

the-lens (TTL) light meter for convenient exposure control.[93][257][258] Had internal cadmium sulfide (CdS) photoresistive

cells mounted behind non-silvered slits in the reflex mirror for coupled center-the-needle, open aperture, full area

averaging metering with auto-diaphragm lenses.[259][260]Film is rated at a particular "speed" sensitivity. It needs a specific

amount of light to form an image. The Weston Universal 617 (USA) helped introduce light exposure metering by a

handheld selenium photoelectric device to sense the ambient light in 1932,[261][262][263][264][265] but miniature light meters built

into the camera that gave TTL readings were a great leap forward in convenience[266] introduced by the Feinwerk

Technik Mec 16SB (West Germany) non-SLR subminiature (10×14 mm frames on 16 mm film) camera in 1960.[267]

[268] TTL metering became normal in virtually all 35 mm SLRs by the late 1960s.[197][269] The durable and rugged RE Super

had excellent interchangeable Exakta mount lenses and was the only pro level 35 mm SLR to compete with the Nikon

F (see above) with any success. However, Topcons never progressed and Tokyo Kogaku (or Tokyo Optical) quit the

consumer camera business circa 1980.[270]

1963

Olympus Pen F (Japan): first single frame (also called half frame) 35 mm SLR.[271][272][273][274] Took up to 72 exposures of

vertical 18×24 mm frames on 135 film. Had flat-topped non-pentaprism porroprism reflex and optical relay viewfinder,[111]

[275] and rotary focal-plane shutter.[276][277] Well-integrated compact design with excellent interchangeable lenses and large

accessory system. The original non-SLROlympus Pen (Japan) of 1959 helped give 35 mm still cameras that used the

standard motion picture frame size of 35 mm film a burst of popularity. It ended by the late 1960s.[278][279][280] Although

single frame cameras used standard 135 film, single frame photofinishing was always special-order.[281]

[282] Kyocera/Yashica unsuccessfully attempted to revive the format as "Double 35" with their Yashica Samuraiseries

(Japan) SLRs in 1988.[283]

1964

Asahi (Honeywell in USA) Pentax Spotmatic (Japan): second SLR with coupled center-the-needle TTL metering (stop-

down aperture, full area averaging). Well-integrated, compact and reliable focal-plane shutter, instant return mirror and

pentaprism design with excellent non-auto-diaphragm interchangeable lenses.[284][285][286][287] Although the Spotmatic's stop-

down (manual diaphragm lenses) system was less convenient than the RE Super's open aperture (auto-diaphragm

lenses) system, the Spotmatic's two CdS cells on either side of the eyepiece reading off the focusing screen was less

expensive and complex than the RE Super's system (see above), and thereby more popular.[93][288][289] The Spotmatic's TTL

system was (and is) very influential and widely imitated, often with open aperture. It (and rival TTL metering SLRs,

including the Canon FT [1966; stop-down aperture, partial area],[290][291] Minolta SRT101 [1966; open aperture, modified

centerweighted][292][293] and Nikkormat FTN [1967; open aperture, centerweighted];[294][295] all from Japan) made the

Japanese 35 mm SLR the dominant advanced amateur camera by the late 1960s.[296]

1964

Krasnogorsky Mekhanichesky Zavod (KMZ) Zenit 5 (Soviet Union; Зенит 5): first SLR with built-in electric motor drive.

Had a Ni-Cd battery powered motor for automatic single-frame film advance with a backup film wind knob.[297] In 1970,

the Minolta SRM (Japan) was the first SLR with built-in electric sequential motor drive and first SLR with auto film-rewind.

It was a modified Minolta SRT101 with a permanently bottom-mounted motor drive (eight AA [LR6] batteries) and

detachable handgrip for continuous three frames per second sequence shooting, but no light meter.[298][299][300] Built-in

motor drives did not become common in 35 mm SLRs until the mid 1980s when high-powered, energy efficient "coreless"

micro-motors were perfected, but accessory drives or autowinders taking four to twelve AA (LR6) batteries were very

popular in the 1970s.[301][302] This is, of course, a non-issue in modern digital SLRs.

1964

Kodak Retina Reflex IV (USA/West Germany): first SLR with standard ISO hot shoe atop the pentaprism housing for

direct flash mounting and synchronization.[303] Was a 35 mm, leaf shutter design. A flash is a necessary accessory for

auxiliary or fill light in dim or high contrast conditions. The first camera with any kind of hot shoe connector was

the Univex Mercury (USA) non-SLR half frame 35 mm in 1938 and many post World War 2 non-SLRs (such as the Bell

& Howell Foton [1948, USA] 35 mm rangefinder[304][305]) had a Leica-type accessory shoe with added electrical contact

(the present day ISO hot shoe). Although the Nikon F (see above) had a non-ISO hot shoe surrounding the film rewind

crank in 1959, most 1960s 35 mm SLRs used screw-on accessory shoes attached to the eyepiece to mount flashes but a

PC cable socket to sync them.[306][307] The ISO hot shoe became a standard SLR feature feature in the early 1970s.

However, in 1971, SLRs using "dedicated" electronic flashes with automatic flash exposure control began appearing with

the Canon FTb (Japan). They used ISO-style shoes with extra electrical contacts.[308] Each SLR brand used incompatible

contact configurations and the time of use-any-flash-with-any-SLR passed by the late 1970s. Note, although the hot shoe

had been de facto standardized in the 1950s, the International Organization for Standardization did not promulgate its ISO

518 hot shoe specification until 1977.

1965

Canon Pellix (Japan): first pellicle reflex mirror SLR.[309][310][311][312][313][314] Virtually all SLRs use fast moving reflex mirrors

that swivel out of the way to take the picture, causing mirror shock vibration, blacking-out the viewfinder and delaying

shutter firing. Camera shake can blur the image and the subject (which might have moved) cannot be seen at the instant

of exposure.[111][315][316][317] A fixed semi-transparent pellicle reflex mirror, reflecting 30% of the light to the viewfinder and

transmitting 70% to the film, prevents camera shake and viewfinder blackout, and reduces shutter lag time at the costs of

a dimmer viewfinder image, longer exposure times and possible image quality loss.[318][319] Modern instant return mirrors

are fast enough and have efficient enough shock damping systems that the trade offs are not usually considered

worthwhile.[320][321] Pellicle mirror SLRs are very rare and are usually specialized designs for ultra-high speed (10+ frames

per second) sequence shooting.[322][323]

1966

Praktica Electronic (East Germany) first SLR with an electronically controlled shutter. Used electronic circuitry to time

its focal-plane shutter instead of spring /gear/lever clockwork mechanisms.[324]

1966

Konica Autorex (Japan; called AutoReflex in USA): first 35 mm SLR with successful shutter-priority automation (first

with a focal-plane shutter). The camera also had the rare ability to allow selection between frame sizes (horizontal

24×36 mm or vertical 18×24 mm) between frames on the same roll of film. The camera used a mechanical "trap-needle"

autoexposure system controlled by an external CdS meter that read light directly (not through-the-lens).[197][325][326][327]

1967

Zeiss Ikon Contaflex 126 (West Germany): first Kodapak Instamatic 126 cartridge film SLR. Was a Voigtländer focal-

plane shutter design unrelated to 35 mm Contaflexes (see above), accepting fully interchangeable lenses.[328][329][330] Took

up to twenty exposures of 28×28 mm frames on paper-backed, singly perforated, 35 mm wide film pre-threaded into

double-ended cartridge with film supply and take-up spools.[331][332] Drop-in loading 126 film was introduced in 1963 as

Kodak's first attempt (of many) to solve the problem of amateurs' difficulty in loading 135 film manually. It was briefly an

extremely popular non-SLR snapshot format, but almost dead by 1972.[333][334][335]

1968

Konica Autoreflex T (Japan): first SLR with internal open aperture TTL metering autoexposure (mechanical shutter-

priority).[336][337][338] Was an improved Konica AutoReflex (see above) with internal CdS centerweighted light meter and

reduced shutter button travel, but without half frame capability.[339][340]

1968

OP Fisheye-Nikkor 10mm f/5.6 (Japan): first SLR lens with aspherical elements. Was a 180° orthographic projection

fisheye lens for Nikon and Nikkormat 35 mm SLRs.[341] Typical lens elements have spherically curved surfaces. However,

this causes off-axis light to be focused closer to the lens than axial rays (spherical aberration) and degrading image

sharpness;[342][343][344][345][346][347] especially severe in very wide angle or aperture lenses. This can be prevented by using

elements with convoluted aspheric curves.[348] Although this was understood since the 17th century,[349] the grinding of

aspheric glass surfaces was extremely difficult[350][351] and prevented their consumer use until the E. Leitz 50mm f/1.2

Noctilux (West Germany) in 1966; for Leica M-series 35 mm RFs.[352][353] The Canon FD 55mm f/1.2 AL (Japan) of 1971

was the first rectilinear aspheric SLR lens; for FD mount Canon SLRs,[354][355] and the Asahi SMC Takumar 15mm

f/3.5 (Japan/West Germany) of 1975 was the first rectilinear aspheric wide angle SLR lens; for M42 screw mount Asahi

Pentax SLRs[356] (co-designed with Carl Zeiss [Oberkochen]). The use of modern precision molded plastic or glass

aspheric lens elements has made aspheric lenses common today.

1969

Yashica TL Electro X (Japan): first SLR with all solid-state electronic light metering system. Had a stop-down aperture,

full area averaging, CdS light meter linked via a four transistor circuit board to an extinguish-both-red-over-and-

underexposure-lights exposure control system instead of a galvanometer meter needle. Also had another four transistor

timing circuit to electronically control its metal-bladed Copal Square SE focal-plane shutter.[357][358][359][360]

1969

Asahi (Honeywell in USA) Pentax 6x7 (Japan; name shortened to Pentax 67 in 1990[361]): first 67 medium format SLR.

Took ten exposures of 2¼×2¾ inch (6×7 cm) nominal frames (56×69.5 mm actual frames) on 120 film. The 67 format is

called "perfect" or "ideal," because its aspect ratio enlarges to an 8×10 inch print without cropping. The Pentax 6×7

resembled a greatly scaled-up 35 mm SLR.[356][362][363]

[edit]1970s

1970

Mamiya RB 67 (Japan): first 67 medium format system SLR. Took ten exposures of 2¼×2¾ inch (6×7 cm) nominal

frames (56×69.5 mm actual frames) on 120 film. Also had "revolving" rotatable interchangeable film backs to easily take

vertical photographs with the normally horizontal format and standard interchangeable waist level viewfinder.[364][365]

1971

Asahi SMC Takumar lenses (Japan): first all multicoated (Super-Multi-Coated) lenses for consumer cameras; for M42

screw mount Asahi Pentax SLRs.[366][367] Process co-developed with Carl Zeiss (Oberkochen, West Germany). Lenses with

glass elements "single-coated" with a very thin layer (about 130–140 nanometers[368]) of magnesium or calcium fluoride to

suppress flare producing surface reflections[369] were invented by Carl Zeiss (Jena, Germany) in 1936[370][371][372] and first

sold in 1939.[373] They became standard for high quality cameras by the early 1950s. Coating lenses with up to a dozen

different layers of chemicals to suppress reflections across the visual spectrum (instead of at only one compromise

wavelength) was a logical progression.[374][375]

1971

Asahi Pentax Electro Spotmatic (Japan; name shortened to Asahi Pentax ES in 1972; called Honeywell Pentax ES in

USA[376][377]): first SLR with electronic aperture-priority (using stop-down TTL metering) autoexposure plus electronically

controlled shutter.[172][378][379] Earlier mechanical AE systems tended to be unreliable, but reliable and convenient AE

systems (as well as other electronic control systems) that electronically set either the camera shutter speed or lens

aperture from light meter readings once the other was manually set began with the Electro Spotmatic. Rival electronic AE

SLRs included the Canon EF (1973; shutter priority),[380][381] Minolta XE–7 (1975; aperture priority)[382][383] and Nikkormat

EL (1972; aperture priority),[384][385] all from Japan. Electronic AE came to most 35 mm SLRs by the late 1970s. The

Japanese electronic AE SLR effectively ended the German camera industry when they failed to keep up with their

Japanese counterparts. After ailing throughout the 1960s, such famous nameplates as Contax, Exakta, Leica, Rollei and

Voigtländer went bankrupt, were sold off, contracted production to East Asia, or became boutique brands in the 1970s. [386]

[387][388][389][390][391]

1971

Praktica LLC (East Germany): first interchangeable lens camera with electric contact lens mount, first camera with

electromechanical lens diaphragm stopdown control.[204][392][393] Had M42 screw mount modified for open aperture metering.

The M42 mount was a very popular interchangeable lens mount system for a quarter century. It was used by almost two

dozen different SLR brands, most notably Asahi Pentax.[394] (Asahi became so closely associated with this mount that it

was, and still is, often erroneously referred to as the Pentax screw mount.[395][396]) However, by the early 1970s, the M42's

limitations, especially no provision for auto-diaphragm lens open aperture viewing and metering, were becoming serious

liabilities. After unpopular and uncoordinated attempts to modify the screw mount to support auto-diaphragm lenses with

open aperture metering,[397] Asahi abandoned the M42 screw mount in 1975,[398] effectively ending production of this lens

mounting system.

1971

Fujica ST701 (Japan): first SLR with silicon photodiode light meter sensors.[399][400] Early SLR TTL meters used cadmium

sulfide (CdS) cells (see Topcon RE Super and Asahi Pentax Spotmatic above), as they were the first sensors small

enough to be internally mounted. However, CdS needed fairly bright light and suffered from a "memory" effect where it

might take 30 seconds or more to respond to a light level change.[401] Although silicon's infrared response required blue

filtration to match the eye's spectral response,[402] silicon supplanted CdS by the late 1970s because of its greater

sensitivity and instantaneous response.[403]

1972

Fujica ST801 (Japan): first SLR with viewfinder light emitting diodes.[404][405][406] Had a seven LED dot scale to indicate

extreme overexposure, +1 EV, +½ EV, 0 (correct exposure), –½ EV, −1 EV, extreme underexposure readings of its silicon

photodiode light meter,[407] instead of the traditional but delicate galvanometer needle pointer.[408] A sister camera,

the Fujica ST901 (Japan) of 1974, was the first SLR with a viewfinder LED digital data display.[405][409] It had calculator-

style LEDs showing camera's aperture priority autoexposure set shutter speeds from 20 to 1/1000 second in 14

nonstandard steps.[410]Although they were replaced by more energy efficient and informative LCDs in the 1980s (see

Nikon F3, below), the use of LEDs in the ST801/ST901 were major steps in the escalation of electronics in 1970s camera

design

1972

Olympus OM-1 (Japan): first compact full-featured 35 mm SLR. At 83×136×50 mm and 510 g, it was about two-thirds the

size and weight of most earlier 35 mm SLRs.[296][411][412][413] Excellent mechanical design with excellent interchangeable

lenses and large accessory system. Note that the initial production batches were marked as the M-1, but this designation

was quickly changed when E. Leitz objected over conflicts with their Leica M-series RFs trademarks.[365][414][415][416] M-1

marked cameras are currently a collector's item SLR.

1972

Polaroid SX-70 (USA): first instant film SLR. Had non-pentaprism mirror reflex system and electronic autoexposure in

flat-folding body with bellows and fixed 116mm f/8 lens. Took ten exposure, 3⅛×3⅛ inch frame Polaroid SX-70 instant film

packs.[93][296][417][418][419][420] The principle of self-developing "instant photography" came to Edwin Land in 1943. The first

production instant camera was the non-SLRPolaroid Land Model 95 (USA) of 1948, producing sepia-toned, peel-apart

pictures.[245][421][422][423][424] Steady improvements culminated in the seven year, nearly quarter-billion dollar SX-70 camera

and film project to create full-color, self-contained, develop-before-your-eyes, "garbage-free" prints.[425][426]

1974

Vivitar Series 1 70–210mm f/3.5 (USA/Japan): first professional-level quality close focusing "macro" zoom lens for

35 mm SLRs.[427][428][429] Early zoom lenses often had very inferior optical quality compared to prime lenses,[430][431] but

improvements in computer assisted zoom lens design[432] and construction allowed annual Japanese 35 mm SLR zoom

lens production to surpass prime lenses in 1982[433] and zooms became normal on virtually all but the highest end still

cameras by the late 1980s.[434][435] Ponder & Best's designed in the USA/made in Japan Vivitar Series 1 lenses were

among the best available (many were the first of their kind) for about a dozen years, before new owners debased the

brand.[436]

1975

E. Leitz APO-Telyt-R 180mm f/3.4 (West Germany): first apochromatic lens for consumer cameras (Leicaflex series

SLRs).[437] The refractive index of glass increases from red to blue of the light spectrum (color dispersion). Blue is focused

closer to the lens than red causing rainbow-like color fringing (chromatic aberration).[438][439][440][441][442][443] Most photographic

camera lenses are achromatically corrected to bring blue and red to a common focus – leaving large residual green and

violet chromatic aberrations[444][445] that degrades image sharpness; especially severe in long focus or telephoto lenses.

[446] If red, green and blue are brought to a common focus (plus other aberration corrections) with very little residual

aberration, the lens is called apochromatic.[447][448][449] Chromatic aberration was an issue at the dawn of photography

(daguerreotypes [invented 1839] were blue sensitive only, while the human eye focused primarily using yellow[450]), but

apochromatic photographic lenses were considered unnecessary until the dominance of color film. The use of extra-low

dispersion glasses[451] made most 1980s professional telephotos[452][453][454] and many 1990s amateur telephoto zooms

apochromatic.

1975

Mamiya M645 (Japan): first 645 medium format system SLR. Took fifteen exposures of 2¼×1⅝ inch (6×4.5 cm) nominal

frames (56×41.5 mm actual frames) on 120 film.[455][456] Mamiya was never successful at producing 35 mm SLRs, despite a

half dozen attempts between 1959 and 1980.[457] However, it was a leader in medium format cameras; first with

the Mamiya C series (1956, Japan),[458] the only successful interchangeable lens twin-lens reflex (TLR) cameras ever

made,[162][459] and then with the RB67 (see above) and M645 series SLRs.

1975

Olympus OM-2 (Japan): first SLR with TTL, off-the-film (OTF) flash autoexposure.[460] Had two rearward-facing silicon

photodiodes in the mirror box to meter light reflecting off the film.[461] Circuitry could detect when enough light was exposed

and automatically quench a specially "dedicated" accessory Olympus Quick Auto 310 electronic flash.[462][463][464]

[465] Manual flash exposure control for a natural look is complex and convenient TTL autoflash metering became standard

in virtually all SLRs by the mid 1980s.[365]

1976

Canon AE-1 (Japan): first SLR with microprocessor electronics.[466] Well-integrated and compact shutter-priority

autoexposure design with excellent interchangeable lenses and large accessory system.[467][468][469] Backed by a major

advertising campaign, including celebrity endorsements, TV commercials and a catchy slogan ("So advanced, it's

simple."),[470][471][472] that targeted snapshooters, the AE-1 sold five million units[473] and immediately made the 35 mm SLR

an important mass-market camera.[365][474] An improved model, the Canon AE-1 Program (Japan) of 1981,[475] added

another four million units to the tally.[476]

1976

Asahi Pentax ME (Japan): first autoexposure-only SLR. Had aperture-priority exposure control only (photographer could

not manually select a shutter speed) for simple snapshooter operation.[477][478][479][480]Interchangeable lens autoexposure-

only SLRs disappeared in the mid 1980s, because even snapshooters demanded that SLRs (as "good cameras") have a

manual mode.[481] However, most recent amateurs never use manual control and even some professionals depend on

autoexposure, making the great majority of modern SLRs de facto autoexposure-only cameras.[482]

1976

Minolta 110 Zoom SLR (Japan): first Pocket Instamatic 110 cartridge film SLR. Had built-in zoom lens (fixed 25–50mm

f/4.5 Zoom Rokkor-Macro).[483][484][485] Took up to 24 exposures of 13×17 mm frames on paper-backed, singly perforated,

16 mm wide film pre-threaded into double-ended cartridge with film supply and take-up spools.[486] Compact, drop-in

loading 110 film was introduced by Kodak in 1972. It was briefly an extremely popular non-SLR snapshot format but

almost dead by 1982.[334]

1977

Fujica AZ-1 (Japan): first interchangeable lens camera to be sold with a zoom lens as the primary lens. The AZ-

1's Fujinon-Z 43-75mm f/3.5-4.5 zoom, despite its modest specifications, was the earliest attempt to supersede the

35 mm SLRs heretofore standard 50 to 58 mm "normal" prime lens with today's ubiquitous zoom lens. The regular

Fujinon-Z 55mm f/1.8 lens remained a popular option.[487][488] The AZ-1 was also one of the last Japanese-made M42

screw mount cameras released.[489][490] The purchase of a zoom instead of a prime as the first lens became normal with

virtually all amateur 35 mm SLRs in the latter 1980s.[491]

1977

Minolta XD11 (Japan; called XD7 in Europe, XD in Japan[492]): first dual mode autoexposure SLR. Had both aperture-

priority and shutter-priority autoexposure.[493][494][495][496][497][498] Previously, each AE SLR brand offered only one or the other

mode, and aggressively touted their choice as superior to other.[499] The XD11 offered both modes and trumped the

debate.[500]

1978

Canon A-1 (Japan): first SLR with an electronically controlled programmed autoexposure mode. Instead of the

photographer picking a shutter speed to freeze or blur motion and choosing a lens aperture f-stop to control depth of field

(focus), the A-1 had a microprocessor computer programmed to automatically select a compromise exposure from light

meter input.[501][502][503][504][505] Virtually all cameras had some sort of program mode or modes by the mid-1980s. It was also

the first camera to have all four of the now standard PASM (program/aperture-priority/shutter-priority/manual) exposure

modes. Canon's long term emphasis on the highest possible technology eventually allowed the company to dominate the

35 mm SLR market; first at the amateur level, with their AE-1 (see above) and A-1,[365][506][507] and then (despite a stumble

in the mid 1980s when they came late to autofocus) the professional level in the early 1990s with the Canon EOS-

1 (Japan) of 1989.[508] Canon remains the leading digital SLR maker, with a 38% worldwide market share in 2008.[509]

1978

Polaroid SX-70 Sonar (USA): first electronic autofocus SLR. Had active ultrasonic sonar echo-location rangefinder AF

system. This unique-to-Polaroid AF system had no influence on any other type of AF SLR. Took ten exposure, 3⅛×3⅛

inch frame, Polaroid Time-Zero SX-70 instant film packs.[510][511][512][513][514]

1978

Asahi Pentax Auto 110 (Japan): first interchangeable lens Pocket Instamatic 110 film system SLR. Mini-35mm SLR-like

programmed autoexposure design with good interchangeable lenses and large accessory system.[515][516][517][518] Was the

smallest and lightest SLR ever made – 56×99×45 mm, 185 g with Pentax-110 24mm f/2.8 lens.[519][520][521] The Auto 110

and its improved successor, the Pentax Auto 110 Super (Japan) of 1982, were the only interchangeable lens 110 SLRs

ever produced and the most advanced 110 cameras ever made, but were unable to prevent the demise of 110 film. [522][523]

1979

Konica FS-1 (Japan): first SLR with built-in motorized autoloading.[524][525] Also had autowinding (motorized single frame or

continuous up to 1.5 frames per second film advance), but not auto-rewind.[526][527][528] A snapshooter's great dislike (and

Kodak bugbear) of 135 film was the need to manually thread the film leader into the camera's take-up spool. [529] Built-in,

motorized, automated film-transport systems (auto-load/wind/rewind) arrived with the Canon T70 (Japan) in 1984.[530]

[531] Completely automated film handling systems appeared when automatic "DX" film speed setting was added to auto-

transport in the Minolta Maxxum 7000 (Japan; see below) in 1985[532] and became standard in virtually all 35 mm SLRs

by late 1980s. This is, of course, a non-issue in modern digital SLRs. Although Konishiroku has a rich history including

several first rank camera innovations, it was never able to establish Konica as a first tier brand and quit the SLR business

in 1988.[533][534][535]

1979

Asahi Pentax ME Super (Japan): first SLR with primarily electronic push button controls. Had increase/decrease push

buttons for shutter speed selection instead of a traditional shutter speed dial.[479][536][537][538][539] As digital computerized SLR

features multiplied, push button controls also multiplied and replaced analogue electromechanical dial switches in most

35 mm SLRs by late 1980s.

1979

Sedic Hanimex Reflex Flash 35 (Australia/Japan): first SLR with built-in electronic flash. Otherwise a wholly forgettable

camera; a cheaply made 35 mm SLR of low specifications and poor quality, with a fixed Hanimar 41mm f/2.8 lens and

mirror gate shutter.[540]

[edit]1980s

1980

Nikon F3 (Japan): first SLR with viewfinder liquid crystal display digital data display. LCD showed shutter speeds; manual

mode and under/overexposure indicators.[541][542][543][544][545] As computerized SLR features multiplied, comprehensive

viewfinder LCD panels became normal in virtually all 35 mm SLRs by late 1980s

1981

Rolleiflex SL 2000 F[546] (West Germany): first 35 mm SLR to not use the oblong body plus viewfinder head configuration

and handling established by the Kine Exacta, 45 years before (see above). Had a cubic body, like a miniature 2¼ medium

format SLR, with fixed dual telescopic eyelevel plus folding waist level finder. Also had interchangeable film backs, built-in

motor drive, aperture priority AE and TTL autoflash.[547][548][549] The 1980s saw varied attempts to stand out in a crowded

marketplace by using unconventional 35 mm SLR body layouts.[550][551] Besides the professional level Rolleiflex, they

included the vertical Yashica Samurai series[552] and the flat Ricoh Mirai[553][554] (both 1988 and from Japan) point-and-

shoot SLRs.[555][556] They were all unsuccessful in establishing a new paradigm and the rectangular body plus pentaprism

head layout reemerged universal again in the early 1990s, albeit usually with a large handgrip and rounded contours.

1981

Pentax ME F (Japan): first built-in autofocus 35 mm SLR. Had passive contrast detection AF system.[337][557][558][559]

[560] Autofocused poorly and was not commercially successful.[561][562][563][564] Also hadPentax K-F mount, a unique bayonet

lens mount with five electric contact pins to pass focus control information between the ME F and its unique

autofocusing SMC Pentax AF 35mm-70mm f/2.8 Zoom Lens.[565][566][567] Note that the Ricoh AF Rikenon 50mm

f/2 (Japan) lens of 1980 had a self-contained passive electronic rangefinder AF system in a bulky top-mounted box and

was the first interchangeable autofocus SLR lens (for any Pentax K mount 35 mm SLR).[568][569][570]

1981

Sigma 21-35mm f/3.5-4 (Japan): first super-wide angle zoom lens for SLRs. For decades, combining the complexities of

rectilinear super-wide angle lenses, retrofocus lenses and zoom lenses seemed impossibly difficult. Sigma did the

impossible[571] and reached a 91° maximum field of view for 35 mm SLRs with an all-moving eleven element formula

through the maturation of computer-aided design and multicoating.[572] In 2004, the Sigma 12-24mm f/4.5-5.6 EX DG

Aspherical HSM (Japan) zoom reached 122°, wider than any SLR prime lens ever made, by taking additional advantage

of aspherics and low dispersion glasses.[573]

1982

Ricoh XR-S (Japan): first solar powered SLR.[574] Was a Ricoh XR-7 (Japan) aperture priority AE 35 mm SLR of 1981

modified with two silicon photovoltaic cells in the sides of the pentaprism housing that charged a unique 3 volt 2G13R "5-

year" rechargeable silver oxide battery. This battery could be replaced with two regular 1.5 volt S76 (SR44) silver oxide

batteries.[575][576][577] The XR-7 and XR-S also had unusual viewfinder LCD showing meter pseudo-needle pointing along an

analogue shutter speed scale to indicate light meter recommended settings, mimicking a traditional galvanometer needle.

[578][579]

1982

Polaroid SLR 680 (USA): first high-quality SLR with built-in electronic flash. Also had active sonar echo-location AF

system. Took ten exposure, 3⅛×3⅛ inch frame Polaroid 600 instant film packs. Was improved Polaroid SX-70 Sonar (see

above) AF SLR with almost-all plastic (acrylonitrile butadiene styrene [ABS]) body, built-in flash and faster film.[580][581][582]

[583] The SLR 680 represents the zenith of instant photography and was the finest instant camera ever made. For a time in

the 1960s and 70s, Polaroid instant cameras outsold all other high-end cameras combined,[584] but the popularity of instant

photography waned throughout the 1980s[585] as auto-everything 35 mm point-and-shoot cameras and fast one-hour film

developing became common.[586] Polaroid went bankrupt in 2001.

1983

Pentax Super A (Japan; called Super Program in USA): first SLR with external LCD data display. With push buttons for

shutter speed selection instead of a shutter speed dial, the Super Program used an LCD to show set shutter speed. [587][588]

[589] As computerized SLR features multiplied, large external LCD panels became normal on virtually all 35 mm SLRs by

the late 1980s.

Nikon FA (Japan): first camera with multi-segmented (or matrix or evaluative; called Automatic Multi-Pattern) light meter.

The FA had a built-in computer system programmed to analyze light levels in five different segments of the field of view

for convenient exposure control in difficult lighting situations.[338][590][591][592][593][594][595][596] After TTL SLR meters were

introduced by the Topcon RE Super in 1963 (see above), the various SLR manufacturers tried many different sensitivity

schemes (full area averaging, centerweighted, partial area and spot were the most common[597]) in the 1960s before

settling in the mid-1970s on centerweighted as the best (90% acceptable exposures[598]) available system. AMP cut the

error rate by half.[599] Matrix meters became virtually standard in 35 mm SLRs by 1990 and modern ones are virtually

100% technically accurate. Note however, the technically correct "18% gray" exposure is not necessarily the artistically

desirable exposure.[599][600][601][602] In 1996, the number of computer analyzed segments reached a maximum of 1005 in

the Nikon F5 (Japan).[603]

Olympus OM-4 (Japan): first camera with built-in multiple spot-meter (2% of view; 3.3° with 50mm lens). Meter could

measure eight individual spots and average them for precise exposure control in difficult lighting situations.[604][605][606]

[607] Spotmeters versus matrix meters represent the opposite ends of the light meter spectrum: fully manual contemplative

metering versus completely computerized instantaneous metering.[608][609]

Minolta Alpha 7000 (Japan; called Maxxum 7000 in USA, 7000 AF in Europe[610]): first commercially successful

autofocus 35 mm SLR, first passive phase comparison AF SLR, first system AF SLR, first SLR with completely automated

film handling (auto-load/wind/rewind/speed setting). Well-integrated PASM autoexposure and built-in motor winder design

with very good interchangeable lenses and large accessory system.[611][612][613][614][615][616][617] Ever since the first autofocus

camera, the non-SLR Konica C35 AF 35 mm P/S of 1977 (with its built-in passive electronic rangefinder system),[365][618]

[619][620][621][622] AF had been common in 35 mm point-and-shoot cameras. The phenomenal success of the Maxxum

temporarily made Minolta the world's number one SLR brand[623] and permanently made the AF SLR the dominant 35 mm

SLR type. Minolta suffered major reverses in the 1990s and was forced to merge with Konica in 2003, and then to transfer

its technology to Sony and quit the camera business in 2006, after selling 13.5 million Maxxums.[624]

Kiron 28-210mm f/4-5.6 (Japan): first very large ratio focal length "superzoom" lens for still cameras. Was first 135 film

zoom lens to range from standard wide angle to long telephoto;[625][626][627] albeit with a small variable maximum aperture to

keep size, weight and cost within reason.[628] Although the 10 to 1 ratio Angénieux 12-120mm f/2.2 (France) zoom had

been introduced for 16 mm movie cameras in 1961,[629] and consumer Super-8 movie and Betamax/VHS video cameras

long had superzooms, early 35 mm SLR zoom focal length ratios rarely exceeded 3 to 1, because of 135 film's much

higher acceptable image standards. Despite their many image quality compromises,[630][631] convenient superzooms

(sometimes with ratios over 10 to 1) became common on amateur level 35 mm SLRs by the late 1990s.[632] They remain a

standard lens on today's amateur digital SLRs, with the Tamron AF18-270mm f/3.5-6.3 Di II VC LD Aspherical (IF)

MACRO attaining 15× in 2008.[633][634][635] Note, the Canon DIGISUPER 100 xs, a 100× (9.3-930mm f/1.7-4.7; Japan)

broadcast television zoom lens, was introduced in 2002.[636]

Pentax SFX (Japan; called SF1 in USA): first interchangeable lens SLR with built-in electronic flash (first built-in flash with

TTL autoexposure in any camera).[637][638][639] Built-in electronic flashes for convenient auxiliary light in dim situations or for

fill-light in high contrast situations first appeared on the non-SLR Voigtländer Vitrona (West Germany) of 1964[640] and

had been common on point-and-shoot cameras since the mid 1970s.[641] Built-in TTL autoflashes became standard on all

but the most expensive 35 mm SLRs cameras by the early 1990s.[642]

Canon EF mount (Japan): first all-electronic contact camera lens mount for interchangeable lens cameras. Introduced

by Canon EOS 650[561][643] and EOS 620[644][645] 35 mm SLR bodies and Canon EF lenses, this lens mount is essentially a

computer data port. Mechanical camera-to-lens linkages can link auto-diaphragm lenses and instant return mirror, focal-

plane shutter SLRs, but electronic autofocus required additional electronic data exchange between camera and lens.

Canon decided to place everything under electronic control, even though it meant that earlier Canon lenses would not be

usable with the new bodies.[296][646][647][648]

Minolta Maxxum 7000i (Japan; called Dynax 7000i in Europe, Alpha 7700i in Japan[649][650][651]): first multi-sensor (three,

in an "H" pattern) passive autofocus SLR. First generation AF SLRs had a single central AF sensor. However,

composition rules generally say it is wrong to have dead center subjects[652] and most compositions have off-center

subjects. Multiple AF sensor arrays covering a wide area can more easily focus on these compositions.[653][654][655][656] In

2007, the number of AF sensors reached 51 in the Nikon D3[657] and D300[658] (Japan) digital SLRs. In 1990, the 7000i and

a sister camera, theMinolta Maxxum 8000i (Japan, 1990),[659][660][661] were also the first 35 mm SLRs with available

"panoramic" format film gate mask and focusing screen accessory.[662] Introduced in 1989 by the Kodak Stretch 35 (USA)

single-use camera, this 13×36 mm frame on 135 film with 3½×10 inch prints was a faddish snapshot format during the

1990s.[663][664]

Yashica Samurai Z-L (Japan): first SLR intentionally designed for left-handed operation. Took up to 72 exposures of

horizontal 18×24 mm single frames (also called half frames) on 135 film. Had flat-topped non-pentaprism mirror reflex and

optical relay viewfinder. Also had unique-to-Samurai-series vertical body design with fixed autofocus 25–75mm f/4–5.6

zoom lens, interlens leaf shutter, programmed autoexposure, built-in motor drive and electronic flash. Was mirror copy of

auto-everything, point-and-shoot Samurai Z camera.[552][665][666]

Kodak Digital Camera System DCS (USA/Japan): first digital still capture SLR. Was a heavily modified Nikon

F3 (Japan) 35 mm SLR and MD-4 motor drive with 1024×1280 pixel (1.3 MP) charge-coupled-device (CCD) sensor, 8 MB

DRAM memory and a tethered 200 MB (160 images) Digital Storage Unit (DSU) hard drive. Used manual focus Nikon F

mount lenses with 2× lens field of view factor compared to standard 135 film. List price was US$19,995[667] (standard

Nikon F3HP was US$1295 list; MD-4, US$485[668]). Electronic still (then using analogue processing and called still

video[669]) photography was first publicly demonstrated by original Sony Mavica (Japan) 490×570 pixel (280 kP) CCD,

prototype SLR camera in 1981.[670][671] The Institute of Electrical and Electronics Engineers has called the DCS's Kodak

KAF-1300 (USA, 1986) image sensor one of "25 Microchips That Shook the World" because the DCS began the digital

photography revolution.[672] Digital photography did not alter the basic focal-plane shutter, instant return mirror,

pentaprism, auto-diaphragm lens, TTL meter, autoexposure and autofocus formula of SLR camera design developed over

the previous century – except, of course, it is filmless.

Nikonos RS (Japan): first waterproof 35 mm system SLR for 100 m maximum depth, underwater diving use. Had

autofocus, autoexposure, TTL autoflash, excellent interchangeable lenses and good accessory system.[673][674][675]

Canon EF 75-300mm f/4-5.6 IS USM (Japan): first SLR lens with built-in image stabilization (called Image Stabilizer; for

Canon EOS 35 mm SLRs). Had an electromechanical system to detect and counteract handheld camera/lens

unsteadiness, allowing sharp photographs of static subjects at shutter speeds much slower than normally possible without

a tripod.[676][677] The first stabilized lens for consumer cameras was the 38-105mm f/4-7.8 lens built into the Nikon Zoom-

Touch 105 VR (Japan) 35 mm point-and-shoot of 1994.[678] Image stabilized lenses were initially very expensive and used

mostly by professional photographers.[679][680] Stabilization surged into the amateur digital SLR market in 2006.[681][682][683][684]

[685] However, the Konica Minolta Maxxum 7D (Japan) digital SLR introduced the first camera body-based stabilization

system in 2004[686][687] and there is now a great engineering and marketing battle over whether the system should be lens-

based (counter-shift lens elements) or camera-based (counter-shift image sensor).[688][689][690]

Minolta Vectis S-1 (Japan/Malaysia): first Advanced Photo System (APS) IX240 film SLR.[691][692] Took up to forty

exposures of 16.7×30.2 mm frames on polyethylene napthalate base, singly perforated 24 mm wide film coated with

invisible magnetic data encoding stripe, pre-loaded into self-locking ready-to-use cartridges.[693] Had flat-topped non-

pentaprism sideways mirror reflex and optical relay viewfinder.[694] Compact design with good lenses and large accessory

system. APS film was introduced by Kodak, Canon, Fuji, Minolta and Nikon in 1996 as Kodak's last attempt (of many) at

drop-in film loading.[334] APS was moderately popular, but faded quickly and almost dead by 2002.[695]

Canon EOS D30 (Japan): first complementary metal-oxide-semiconductor (CMOS) sensor digital SLR; first digital SLR

intended to be a relatively affordable, advanced amateur level camera. Took up to 1440×2160 pixel (3.11 MP) digital

images. Used Canon EF mount lenses with a 1.6× lens factor, compared to 135 film.[696] The use of a cheaper and lower

quality CMOS sensor[697] allowed a price (US$3499 initial list price; US$2999 in 2001; body only) about half of

contemporary professional CCD digital SLRs; giving ambitious amateurs the choice of an interchangeable lens digital

SLR, in addition to the digital point-and-shoots common in the late 1990s.[698][699]

Canon EOS Kiss Digital (Japan; called EOS Digital Rebel in USA, EOS 300D Digital in Europe[700]): first sub-US$1000

high-resolution digital SLR. Well-integrated focal-plane shutter, instant return mirror, pentamirror, auto-diaphragm,

autoexposure, matrix-metering, autofocus, built-in autoflash, computer-controlled design with excellent lenses and good

accessory system. Took up to 2048×3072 pixel (6.3 MP) digital images using a 15.1×22.7 mm complementary metal-

oxide-semiconductor (CMOS) sensor (1.6× lens factor). With an original list price of US$899 (body only; US$999 with 18-

55mm f/3.5-5.6 Canon EF-S zoom lens),[701] it sold 1.2 million units around the world in sixteen months[702] and was

primarily responsible for digital SLR sales vaulting past film SLR sales worldwide in 2004.[703][704][705][706]

Olympus Evolt E-330 (Japan): first live view digital SLR. Had a secondary CCD sensor to send a live video feed to a

swiveling 2.5-inch (64 mm) color LCD panel (normally used for camera function data) and allow its use as an auxiliary

viewfinder when the photographer's eye cannot be at the SLR viewfinder eyepiece. A sharper live view mode was

available that temporarily flipped aside the reflex mirror (blacking out the primary porro-mirror SLR viewfinder) and opened

the shutter to send a live feed from the primary 2352×3136 pixel (7.5 MP) Four Thirds format MOS image sensor.[707] Most

new for 2008 digital SLRs had a live view mode.[708] Although today live view has limitations (unintelligibility in bright

sunlight, image lag with moving subjects, rapid battery drain, etc.), its perfection, plus an electronic shutter, would make

the bulky and expensive precision mechanisms and optics of a focal-plane shutter, instant return mirror and pentaprism

unnecessary and allow the camera to be a completely electronic device. (This has already occurred with snapshot

cameras – the vast majority of point-and-shoot digital cameras lack an optical viewfinder.) In other words, the Micro Four

Thirds format Panasonic LUMIX DMC-G1 (Japan, 2008) mirror-less non-SLR, interchangeable lens digital camera with

high resolution electronic live view viewfinder and LCD[709] might be the first of a new breed of camera with the potential to

end the history of the single-lens reflex camera.[710][711][712][713][714][715]

Nikon D90 (Japan): first digital SLR with high definition video recording capability. Had 12.3 MP APS-sized CMOS sensor

with secondary 1280×720 pixel (720p), 24 frames per second HD video capture with monaural sound for five minutes in

September.[716][717][718][719] Two months later, the Canon EOS 5D Mark II (Japan) 21.1MP full-frame CMOS D-SLR came out

with 1920×1080 pixel (1080p), 30 frame/s HD video with monaural sound (stereo with external microphone) for twelve

minutes.[720][721][722][723] The D90 and 5D II are otherwise straightforward 2008 D-SLRs. Point-and-shoot digital cameras have

had video recording (usually standard definition, but HD recently) for a few years and it is expected that HD video

recording will soon become a standard D-SLR feature.[724]

Sony SLT α33 and SLT α55 (Japan): first SLRs without an optical viewfinder. What appears to be a pentaprism head is a

high resolution electronic viewfinder (EVF). Had 16.2 MP (α55) or 14.2 MP (α33) APS-sized CMOS sensors with

secondary 1080i high definition video capture. Also had a swiveling live view LCD panel. The SLTs' fixed so-called

"Translucent Mirror Technology" reflex mirrors (a revival of pellicle mirrors [see Canon Pellix above]) siphon off light to

their fifteen phase comparison autofocus sensors to provide continuous autofocusing in their HD video mode.[725] [726] [727]

Camera ObscuraThe earliest cameras obscura used only a pinhole, so that the location of the back wall was not critical. They date back to at least 350 BC. The main problem is that the image is very dim for decent resolution. The smallest detail that can be resolved is the diameter of the pinhole.

In order to get useful brightness, a lens must be used. Here another problem crops up--the focal length needs to be equal to the distance from the wall with the lens to the back imaging surface (just as in any "camera"). One can make a simple, long focal length lens by combining a negative and positive lens. For example, a +2.5 diopter (0.4meter focal length) positive lens combined with a -2.0 diopter negative lens will yield a +0.5 diopter power, or a 2 meter focal length.

A panel of foamcore or similar white material placed 2 meters from a blackened window with this example lens in it should provide a good viewing surface. Black plastic sheeting used for protection of floors when painting is pretty opaque, and is good for blacking out windows.

Be prepared for dim images. Suppose the lens diameter in the example is 25mm, yielding an f/no. of f/80. The "brightness" of the image on the screen will be: B(i) = R* B(s)/(4*f^2) where R = Reflectance of the image board (approx. 0.8)B(i) = image brightnessB(s) = scene brightnessf = lens f/no (80 in the example)

For this case, then, the image will be 32,000 times dimmer than the outside world. If the outside is reflecting an average of 3x10^4 lumens/m^2 (midday bright sunlight), about 1 lumen/m^2 will be reflected from the white panel. This is about 10 times the apparent brightness of a scene lit by the full moon at zenith.

The advantages of a small room (camera) are obvious from the equation. The image brightness will increase by a factor of 4 if the dimension is reduced to 1 meter, or decrease by a factor of 4 if the dimension is increased to 4 meters. If you can find a larger aperture lens, the brightness will also benefit by the square of the lens diameter.

ReferencesGernsheim & Gernsheim "the History of Photography" (Oxford University Press; 1955) - Part I contains some historical material on the camera obscura.

John H. Hammond "The Camera Obscura" (Adam Hilger, Bristol; 1981) - a nice little book on the history and existing camera obscura for public viewing in about 1980.

Book three of the series "Amateur Telescope Making" (1956) has a couple of pages on what they call a camera oabcura, (which is sort of a large view camera) but describes the use of a simple meniscus lens with a stop in front of it (described as a

rear landscape lens). The relatively wide field of view of the landscape configuration is a plus in this application.