IMA 751 DOC I • Fall 2017 Lecture 2

The Camera: Origins of the Motion Picture Camera Functionality of the Camera Shooting strategies

Intro to cameras

• The motion picture camera owes its origins to a variety of previous inventions…

The Camera Obscura

• Camera Obscura means “Dark Chamber”. A hole in the wall allowed light to ‘paint a picture’ inside the room.

A Painter’s Tool

• Painters began using the “camera obscura” during the Renaissance to help create ‘realistic’ images.

“View of Delft” by Vermeer

Adding a Lens makes the unit

portable and the image size adjustable

• Artist Using a Portable ‘Camera Obscura’

The Magic Lantern

Adding a light source to the Camera Obscura meant a new form of entertainment. Here we see a Magic Lantern man with his projector.

I’m a Singer

Mass Production &Repetitive Motion were developed in late 19th CenturyDevices such as thesewing machine, the typewriter and the repeating rifle led to the production capability needed to make the movie camera.

The Invention of FilmIn the late 1830’s the development of a science of chemistry meant that inventors in England and France were able to use the chemical properties of SILVER to create images with light.

Talbot was an artist who used a ‘camera obscura’ as a drawing aid. He developed a system using silver nitrate on paper used both for photographs and photograms.

Louis Daguerre invented theIdea of ‘Developing’ a printon a silver plate.

Boulevard du Temple, 1838

Short Range Apparent Motion (persistence of vision)

zoetrope

thaumatrope

The Flip Book

How do we get from this:

To this: Edison Kinetoscopic Record of a Sneeze (Jan. 7, 1894)

Edison’s Kinetograph (1891)

first movie cameras

Lumieres’ Cinematographe (1895)

Film camera : a mechanical device

Movie Film: A chemical medium

• The business part of the film is the thin layer of emulsion, which is light sensitive. The base is made of acetate. In the old days celluloid was used.

how film projectors work

Workers Leaving the Lumiere Factory (1895)

A set of inventions that emerged in the late 1950s and early 1960s quickly became the standard for documentary film production. These included lightweight 16mm cameras such as the Eclair NPR, the zoom lens, the Nagra recorder, and the condenser shotgun mic.

In 1968, “portable” video is born!

1970s: Portapak U-matic

In the 1980s, the camcorder!

The video camera evolves

● CCDs replaces picture tube (1980s)

● Digital recording replaces analog (1990s)

● Solid state media replaces tape (2000s)

● CMOS chips replace CCDs. (2010s)

And in 2005, the DSLR “revolution” (DSLR = Digital Single-Lens Reflex)

● Low cost ● Big sensor = “film look” ● Small size ● Interchangeable, high

quality lenses

Hybrid Video Cameras & DSLRs

insert pics of portapak, ¾, camcorder

In these cameras the form factor and and imaging area of still film cameras has been combined with the capabilities of digital video.

DSP = digital signal processor

Important Variables to Control

Learning to shoot a motion picture camera means learning to control a set of variables, some of which can be set in advance, such as bitrate and frame rate. Other variables include shutter speed or color temperature can be set from time to time while shooting. A third set of variables related to the lens including f-stop, focal length, and of course focus, will be reset continuously as you work.

frame rate

• flip book = 10 fps • old film cameras = 16 fps • modern film cameras = 24 fps • video = 30 or 24 fps

The Shutter

● exposes the film ● blocks light so film can

advance ● for video ... ● Shutter Speed refers to

how much time the shutter is open, allowing light to expose the film.

Shutter speed is generally set to one second divided by twice your frame rate. So at 24fps your shutter speed would be 1/48th of a second.

ISO determines sensitivity to light (on a camcorder this is called Gain)higher ISO = brighter image, more “grain” lower ISO = darker image, less “grain”

The best strategy is to keep gain as low as possible, as noise or grain you can’t see in viewfinder may show up later.

On the C100 set ISO to 200 or 400 On the XF300 set gain to +0

TheLens:theEYEofyourcamera

Lenses bend light (refraction)

and focus it on a focal plane

Lens Variables

• Focus • Focal length• F-stop (aperture)

★

Focusdetermineswhatis(andisn’t) sharpintheframe

Here, the bubble is on the plane of critical focus for this lens at its particular setting.

Automatic vs. Manual Focus

Focus is the first thing you should learn to control manually.

How to focus manually

measure distance from the subject to the focal plane (recording surface)

*Note: make sure you camera is set to “manual focus”

Other ways to focus

zoom in all the way and focus, zoom out OR use focus assist

As long as the distance between the camera and the subject doesn’t change, the subject will stay in focus.

SelectiveFocus

Lens Variables

• Focus • Focal length• F-stop (aperture)

★

Focal length is the distance between the Optical Center of the lens and the recording surface,

and is measured in mm

FocalLengthimpactsAngleofView

A prime lens has afixed focal length(in this case 135mm)

Zoom lenses havevariable focal lengths usually expressed as a

ratio, e.g. “10:1 zoom”

How to adjust focal length

Servo zoom lever (as on Canon XF300)

Manually (as on Canon C100)

FocallengthimpactsDepthofField

Long (telephoto) lenses have shallow depth of fieldWide lenses have deep depth of field

Focal length impacts perspective

Wide angle lenses expand space Long lenses compress space

Whichwastakenwithalongerlens?

Inwhichinstancewasthecameraphysicallyclosertotheactors?

Workflow Considerations

Before shooting figure out your frame rate, pixel dimensions, and the quality level (bandwidth) you plan to shoot at. Figure out how you will store, back up and identify your material.

CANON XF 300

Shooting Considerations:

As you start to shoot identify controls and set your gain, your shutter speed and your white balance manually.

Identify how to manually control your focusand your iris.

CANON XF300

Push to set WB after turning AWB (auto white balance) OFF. You can set two WB’s. Preset can be selected in MENU.

CANON C100 Toggle to change gain/shutter speed

Push to set WB after pushing WB button below.

CANON C100 Auto-focus

(On the Canon XF300 set the Focus M/A button to “A” and use the “Push AF” button above it.)

Key Concepts

● Short-Range Apparent Motion ● Zoetrope ● Photography: Daguerrotype ● Thomas Edison, Louis & Auguste Lumiere ● Portapak, Camcorder, DSLR ● Basic Film Camera & Video Camera Anatomy ● The Shutter & Shutter Speed ● Frame Rate ● Gain / ISO ● Lens ● Focal Plane (film stock or sensor) ● Focus ● Focal length ● Prime (fixed focal length) vs. zoom (variable focal length) lenses ● Depth of Field ● Perspective