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DSLR Time­Lapse

Wispy clouds gently fly past the viewer, thousands of stars rotate in the night sky overhead, and the sun rapidly falls below the horizon revealing the stars in the dusky sky. Einstein wrote that time is relative and we have come to expect events to occur at specified rates. However, through the magic of time­lapse photography, flowers can bloom and die in mere seconds, shadows can race across mountainous landscapes, and city traffic streaks through city highways.

Surely you have seen amazing time­lapse sequences in nature films, on YouTube and Vimeo and even in commercial films. Speeding up the rate at which some events occur will often reveal details that would not be obvious when seen at their normal rate.

Manipulation of time to see events that are not apparent to the unaided eye include high­ speed video to slow down rapidly occurring events and time­lapse photography to speed up events which can occur over minutes, hours, or even days and weeks! High­speed video requires specialized equipment that is rather expensive. Remarkably, time­lapse photography doesn’t require a lot of expensive equipment and most digital cameras are capable of creating these images. Since the images are composed of separate still images, video capability isn’t necessary.

In fact, the very minimum requirements are a digital camera, a steady tripod and lots and lots of patience! Also recommended is a trigger release although you can just press the shutter button repeatedly. Just bear in mind that your final video will be determined by your ability to sit and repeatedly trip the shutter!

More advanced users will want to use automated intervalometers and perhaps even automated camera sliders or motorized heads. Many of these items can be fairly inexpensive and will ensure that you don’t end up going crazy or develop some form of repetitive strain injuries by pressing a camera trigger every few seconds for hours at a time!

History

Motion pictures and video normally are projected at a rate between 24 and 30 frames per second (films are 24, video is 30 fps in the USA and 25 fps in many European countries). Let’s use 24 frames per second to illustrate. That means for every second of screen time, there are 24 individual frames that are sequentially displayed to produce the illusion of motion. The frames per second are the same for capture and playback so the motion appears normal to us.

However, imagine if you took a frame every minute for 24 minutes and then projected them back at the normal rate of 24 fps. Those 24 minutes would flash by in a second of screen time. This is the basis of time lapse. The photographer captures individual frames over an extended period of time, which are played back at their regular rate and suddenly a world of gradually occurring events is magically transformed into something amazing. It allows us to “see” events that normally occur so slowly that we may not even be aware of the motion.

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One of the first photographers to use time lapse was Eadweard Muybridge back in 1872 to help settle a bet on whether a horse has all four feet off the ground at one time. Muybridge was hired by the Governor of California, Leland Stanford to try to settle a bet. It took Muybridge a few years to come up with a system to record such an event and began by firing 24 large glass plate cameras using threads to trip the cameras and then ultimately using a clockwork timing device (the precursor to an intervalometer).

In 1877 he was finally successful in capturing the iconic galloping image on a single negative and proved that a horse indeed has all feet off the ground at one point in a gallop.

Realizing that if these images were projected rapidly, one after the other, this would give the appearance of motion and so the motion picture was born!

In 1898, a German botanist by the name of Wilhelm Pfeffer, the director of the Leipzig Botanical Garden, created the first time­lapse sequence by photographing a tulip over many hours and projecting the images back at regular film speeds to reveal the tulips blooming and dancing on the screen!

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Basics

We have it much easier today than Herr Pfeffer and Mr. Muybridge. Our digital cameras produce image sequences that can be quickly and easily made into video sequences. There are also some additional devices that will make the work and capture even easier!

First of all you need to decide what time base you are going to use for final playback so that you can calculate the number of frames you will need, the period of time to cover and how long will it take to capture these frames.

Yeah, I know. Math sucks. But the math isn’t complicated!

To keep everything easy and to help avoid confusion, I’m going to use a time­base of 30 frames per second for the remainder of this guide in order to simplify the concepts. Once you understand the underlying principals, it is easy to adjust the time­base to 24 fps or 25 fps or whatever you want. I’m using 30 fps because that is the standard video playback speed in the United States and many western countries. Besides, it is better to capture too many frames and speed the sequence up later in your video editor, rather than try to slow it down! Better to drop frames than try to artificially create in­between frames with your video editing software!

For purposes of illustration, let’s say you want to capture a 2­hour event to be played back in 10 seconds. 10 seconds of screen time at 30 fps would require 300 frames. That’s 10 seconds x 30fps = 300 frames. So, we want to capture 300 frames over a 2­ hour period. Two hours contains 120 minutes or 7200 seconds. 7200 seconds divided by 300 frames gives us 24, so we need to capture a frame every 24 seconds for a two­hour period and that would give us the 300 frames we need for our 10­second sequence.

So you see, the math is rather simple (ugh!). You just need to determine how much screen time you want and how long a period you want to compress into that screen time. It just takes some simple math to set up and begin capturing!

Also be aware that if your time between frames is rather short and your exposure time is relatively long, you have to account for the exposure time as well in your calculation. For example, let’s say that you want to record a frame every 5 seconds and will be exposing the frame for 2 seconds. A 2 second exposure every 5 seconds is a total of 7 seconds. 7 seconds times 300 frames is 2100 seconds and divided by 60 seconds means that it will take 35 minutes to record the 300 frames! If your exposure time is short (like 1/30 second or faster), then you likely don’t have to include the exposure time in your calculation, as it isn’t really significant.

There are some rough guidelines to follow depending upon what you are capturing. For moving traffic or fast moving clouds, 1 frame per second works best. For sunsets or sunrises, slower moving clouds, crowds of people, capture a frame every 1 to 3 seconds. For moving shadows across the landscape, the sun moving across the sky, stars at night, you will likely want to capture a frame every 15 to 30 seconds, or even longer. For plants, you may want to capture a frame every 90 seconds to 2 minutes. Basically, the slower the event takes place in real time, the longer the gap between captured frames.

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So, let us assume you want to record a sunset and still want 10 seconds of screen time. That’s our same 300 frames that are required. You decide to record a frame every 2 seconds, so 2 (seconds) x 300 (frames) = 600 seconds or 10 minutes! That means you need to trip the shutter every two seconds for 10 minutes to capture the 300 frames that you need for your final sequence. Simple!

The amount of frames to capture (generally you want at least 10 seconds of screen time) and length of time between frames is a skill that you will quickly acquire a feeling for. Just keep the rough guidelines in mind that I previously discussed.

The time base you choose is only important at this stage for doing your calculations. You can always change your mind when you render your still frames into a video sequence. If you choose 24fps and it is too slow, just render it with a time­base of 30fps and vice versa!

However, who really wants to sit and press a camera shutter every two seconds for 10 minutes, much less every 24 seconds for two hours? Not me, and I’ll bet you don’t either. Fortunately, there are some clever gadgets that you can buy that will perform that task for you!

Equipment ­ intervalometers

Naturally you are going to need a digital camera, and you will need one that will allow you to trigger the camera remotely. This may limit your choices for point and shoot cameras, but most DSLRs should allow remote triggering. There is a possibility that your camera may have an intervalometer built in. Many Nikon cameras have this capability and the new D800 can even combine the frames in camera into an MOV file. If it does, then you may not need a remote trigger, although remote triggers are likely to be more flexible.

You will also need a good solid tripod and head. Since you are going to be recording a sequence over an extended time period, you want to be sure that the camera will not move or shake during the capture. If it does, the final sequence will shutter and shake and will look extremely amateurish. Avoid using the middle riser on tripods and you may also be able to hang some weight on the middle extension in order to prevent the tripod from moving in the wind. For the head, a good ball head or even a video head should work fine. Older, heavy aluminum tripods can often be found used and are ideal for this purpose.

There are lots of options for intervalometers. An intervalometer is a device that you attach to your remote shutter port on your camera and can be programmed to capture frames over a period (interval!) of time. An intervalometer will automate your capture and allow you to take a break while it does all the work!

Many manufacturers have their own dedicated external timers. Nikon and Canon both have units, which sell for around $180 ­ $200. The Canon unit is the TC­80N3 and Nikon’s is the MC­36.

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However there are a number of third parties that make timers that may look identical to the name brand timers for a lot less money. I have a unit from Linkdelight (www.linkdelight.com) for my Canon (they make them for other cameras too) that is only $25 and looks and works exactly like the Canon TC­80N3.

If you do a search on Amazon.com, you will find several third party intervalometers, such as the Satechi, which sells for around $50. Also, Poloroid has a battery grip for the Canon line of cameras that has a built­in intervalometer.

Canon TC­80N3 and Nikon MC­36 Intervalometers

On the higher end, Promote control (www.promotesystems.com) has a unit that sells for about $300 and also can be programmed to do HDR time­lapse. Time­lapse+ (www.timelapseplus.com) has a universal unit for Canon, Nikon, Olympus, Sony, and Pentax. It also offers bulb ramping, which is a special technique to gradually increase or decrease exposure time for sunsets and sunrises. Another high­end intervalometer is the Time Machine (www.bmumford.com/), which sells for about $325 and has advanced capabilities.

The Promote control was originally funded by Kickstarter.com as was the TriggerTrap by Haje Jan Kamps. The Triggertrap V1 can be found at www.triggertrap.com and comes in three flavors: a pre­built model for $199, a shield only (build it yourself model) for $49, and finally, an iPad, iPod Touch, iPhone mobile version which is only $9.99 plus $19.99 for a dedicated camera cable and dongle. The Triggertrap has a lot of additional capabilities to fire a camera based upon certain events (sound, movement, etc.) and I would highly recommend looking into the mobile version.

Enlight Photo also has a mobile intervalometer cable and app available, IOShutter – the cable is $69.96 and $9.99 for the app. Also, onOne (www.ononesoftware.com) has a mobile app and cable available called DSLR Remote.

If you are handy with DIY projects, there are lots of do­it­yourself projects available as well, such as the MX2 Dolly shield from (www.dynamicperception.com ) which is $55 in

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a kit form (you will also need a $30 Arduino chip) or $225 for a pre­built version. I will discuss the MX2 in more detail under camera sliders.

Trigger Trap V1

In addition to the mobile phone devices mentioned above, there are also computer­based applications which require you to tether your camera to your computer or laptop. These aren’t as convenient or portable but there are a number of free and commercial options available. In addition, there are more and more apps being released for both Android and IOS devices.

Equipment – ND filters

Finally, there are a few other extra items that you may wish to consider. In a moment I’m going to discuss “ideal” shutter times, which in some instances can be somewhat long. For reasons yet to be discussed, ND (neutral density) filters may be necessary. You may want a range of filters or may even want to consider a more expensive variable density filter.

ND filters come in two different classifications: either as a filter factor or a filter density. Filter factors are sold as ND2, ND4, etc. and filter densities are sold as .3 ND, .6 ND, .9 ND, etc.

The filter factor lists the amount of extra exposure that is required when the filter is used, so an ND4 would require four times more exposure, or 2 stops. So, you would need to reduce your shutter speed, or aperture by 2 stops to compensate.

Filter density scale is .3 per stop. So, a .9 ND filter would require 3 stops increase in exposure to compensate.

Filters can also be stacked, but extra glass (or plastic!) in front of your lens can lead to odd reflections, reduced sharpness and even vignetting on wide­angle lenses.

For daylight time­lapse, you will likely need at least a 3­stop reduction, so that would be an ND4 or a .9 ND.

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Equipment ­ lenses

Although nearly any advanced digital camera should be able to be used to time­lapse photography (and maybe even some point and shoots!), you will need to consider your choice of lenses. If you are going to be capturing landscape time­lapse sequences, then a wide­angle lens is likely your best choice. Keep in mind your camera sensor size needs to be considered when determining the focal length that you will need. A 20mm lens on a crop sensor DSLR (such as the 1.6 crop on a Canon 7D or the 1.5 crop on Nikons) would give the same angle of view as a 30mm lens on a full frame sensor camera, or a 35mm film camera.

If you are planning to do star trails or night and low light time­lapse sequences, then you will want as fast a lens as you can get (smaller f­stops). Unfortunately, these faster lenses are also more expensive!

Equipment – tripod

You don’t need anything fancy for a tripod, but it should be heavy and secure! It is amazing how much a strong, steady wind can cause a tripod to move slightly. Some tripods have a center hook, from which you can hang additional weight to make sure it remains steady.

The tripod head also doesn’t need to be anything special. It just needs to hold the camera steady during the time you will be recording exposures. Of course, if your sequence is going to cover hours (or days or even weeks and beyond) you must take that into consideration as well.

Equipment – extras

Since your camera is going to be taking many images for an extended period of time (or even long exposures), you will need as much battery power as you can get. External battery packs and battery grips (with extra batteries) can be extremely helpful.

Also, you will likely need extra memory and I recommend you consider getting larger capacity memory cards that are as fast as you can afford. For CompactFlash cards, you should get no less than a 133x speed card and for SD, class 10 cards. The higher speed cards aren’t as necessary if you will be capturing individual frames with extended times in between, but may be necessary if you are going to attempt time­lapse HDR, or will be doing lots of daylight time­lapse in order to prevent the camera buffer from over flowing which will cause you to miss frames.

Issues

There are a few additional issues that must be considered for capturing and creating pleasing time­lapse sequences.

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The aperture and shutters on still cameras can be very accurate and reliable, however, they weren’t intended for the kind of exposure accuracy that is required for time­lapse sequences.

Consider the lens aperture. It is a mechanical device that must move metal (plastic?) blades to reduce the amount of light passing through the lens and then move back into their resting place again. They must do this very quickly for still images – incredibly quickly! Imagine if you take an exposure of 1/5000 second, the aperture must close and open in less than 1/5000 of a second!

Since the aperture is a mechanical device there will always be tiny variations in the amount it closes. Normally this won’t show up and isn’t a problem for regular still images as the amount is quite small. However, for converting our sequence of still images into a video, the tiny variations could cause the final sequence to flicker like an old time movie (yes, I know old movies didn’t flicker when they were new!).

Don’t despair. There are ways to work around this problem!

The first way is to always shoot with the lens wide open. Setting the aperture wide open will mean it doesn’t have to close down and therefore cannot cause tiny exposure fluctuations. There are two disadvantages to this method: depth of field and daylight exposure.

Since the lens is wide open, the lens is at the shallowest depth of field. As you reduce the aperture, the depth of field increases. If you are using a wide­angle lens (which already has a greater depth of field), this may not be a problem. It depends if you have something in the foreground that needs to remain in focus along with the horizon.

The second problem is exposure. When the lens is wide open we will need a lower ISO combined with a faster shutter speed, especially in daylight. As I will point out in a moment, the best­captured motion for time­lapse has a bit of blur so we actually want to drag the shutter (use a slower shutter speed). It is possible that you may not be able to reduce the ISO to a low enough setting for the lens to be wide open and to use a slow shutter speed. This is where ND filters come in handy! Simply add the necessary ND filter(s) onto the lens to reduce the amount of light passing to the sensor.

There are two other techniques that you can use to work around using the aperture wide open.

The first technique (lens twist) may not work on all cameras, but does work on the Canon 5D MK II and the Canon 7D. Set the mode control to Aperture priority (Av on the Canon) or on manual. Set the desired aperture. Now, hold down the depth of field button on the front of the camera body and while continuing to hold it down, carefully press the lens release and rotate the lens slightly. You may now release the depth of field and the lens aperture should remain fixed on the setting you chose. The camera should still be operational, although some cameras may not operate, as they may not detect the lens. You must be careful and only twist the lens a small amount and be careful, as you don’t want the lens falling off if you move the camera!

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The second technique involves using an older lens. Canon cameras will accept adaptors to allow you to use other manufacturer’s lenses (I personally still have my Olympus Zuiko lenses from my OM2 and OM4Ti days!). There is no automatic coupling between the camera and these lenses, so you need to focus and set the aperture manually, but for time­lapse; this is exactly what you want! For Nikon, you can purchase older Nikon mount lenses, which should also fit, but will also have no auto aperture or focus. The glass on these older lenses should still be excellent and you can often pick them up from auction sites very inexpensively!

Shutters are also mechanical and can vary slightly. If the shutter varies by a mere .1%, it will hardly be noticed at 1/30 sec, but could have an impact at 1/5000 of a second!

Fortunately, we want to use slower shutter speeds, so we really don’t need to be too concerned about a slight variance in the mechanical shutter. The reason we want slower shutter speeds is to capture a bit of motion blur in order for the final sequence to look nice and smooth when played back.

The amount of blur that is desirable for any give capture can be easily calculated.

Let us return, for a moment, to our motion picture capture of 24 fps. This is the standard capture and playback speed of modern motion picture film. Since the film is passing through the camera at 24 frames every second, the slowest shutter exposure we can possibly get is 1/24th second.

However, due to the transport of each frame into the gate, we actually can’t capture at 1/24th of a second, as we need to close the shutter momentarily in order to allow the camera mechanism to pull the next frame into place and register it before it is exposed. Motion picture cameras have a disk shutter with a section cut out (usually around 180 to 190 degrees or so). When the cut out portion of the disk is in front of the film, light can pass through. When the opaque part of the disk spins into place, the mechanism can safely pull another frame into place, which is then exposed when the open portion rotates into place again. This allows the camera to pull 24 frames into the camera gate to be exposed for each second. (Many modern motion picture cameras will allow the amount of cutout of the disk to be varied, but that isn’t important to this discussion!).

Since the rotating disk blocks the light for a portion of the 1/24 th of a second, the actual exposure is approximately half of this time, or about 1/40 th of a second. At 1/40 th of a second, some movement that is captured will be blurred on each frame. However, when played back, this blurred motion actually enhances the smoothness of the projected image and looks natural! Without the blur, the projected images would appear odd and have a staccato effect, which was actually used purposely for the Steven Spielberg film “Saving Private Ryan” for the Normandy invasion sequence.

However, for time­lapse, I’m recommending that we actually want to capture a certain amount of motion blur. Our sequences will look a lot more naturally if the people and cars racing through the frame appear to streak around and not just pop in and out of place. If we follow our motion picture example, the “ideal” blur would require a shutter speed that’s about the same proportion of blur as our 24 fps capture. So, a time­lapse sequence that will be captured at 1 frame every three seconds, the “ideal” shutter exposure would

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be around 1.5 seconds – or approximately half of the gap between each captured frame. For clouds and slow moving objects, this will likely be too long and you may have to experiment to find a capture speed that works for each subject.

In some cases, such as HDR time­lapse, that may not be practical and the extra movement may impact the ability to line up the exposures! The total amount of capturing multiple frames may exceed the 3 seconds between frames, and I will cover some of these considerations in the advanced section. In addition, you don’t want too much blur, or some moving objects may disappear entirely! Consider the amount of movement in the frame; little movement will require longer exposure times and rapid movement, shorter times!

Technique

In the previous section I discussed some potential issues with the camera shutter and aperture. However, there are other settings on our digital cameras that we don’t want to change from frame to frame as well! I recommend using manual for everything! Don’t let the camera automatically adjust any setting or you may end up with strange artifacts, color shifts, or other issues such as the nasty flicker problem.

ISO

Choose an ISO setting that is appropriate for the light (considering shutter speed and aperture, of course!). Also consider how much noise you are willing to tolerate. For low­light time­lapse sequences, you may wish to use higher ISO settings, but consider the amount of noise your particular camera produces at higher ISO settings. Manufacturers are managing to reduce noise levels and permit usable higher ISO settings for each generation camera that comes on the market. Currently, on my Canon, I would likely limit the upper ISO to no more than 3200. However, I recommend you avoid using Auto ISO, as this setting will be more than likely to create flicker in your final sequence.

White balance

The same logic applies to your white balance setting. Set it with custom white balance, or choose one of the camera presets, but don’t use the auto setting. If you do, you may experience annoying color shifts from frame to frame.

Focus

Likewise with the focus! Turn off auto­focus (usually a setting on the lens). You don’t want the camera to be changing focus between each frame. In addition, by leaving on auto focus, you may increase the time for the camera to check focus and capture a frame, which could result in dropped frames. This is a bad thing!

Mode

Once again, I recommend using the manual setting! You can determine the exposure beforehand by putting your camera on one of the automatic settings, scan around the scene you’re are going to capture and then set the aperture and shutter speed manually. If

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you are doing low light captures using the intervalometer to control the shutter speed, then you will likely need to set the camera on Bulb setting. Bulb will keep the shutter open as long as the camera shutter button (or cable release) is pressed.

Before we continue, here is a little trivia about the origin of the “bulb” setting. In the early days of photography (back in the mid 1800s), glass and metal plates needed a lot of light to expose them. So, the photographers would trigger the cameras with a squeeze bulb and hold it for the time required for the exposure and then let go, or set off flash powder. That is why the time exposure shutter control today is still called “bulb”.

File Format

Your choice of which file format to use is largely a personal one. If you want the maximum amount of control over each frame, then you will want to use the RAW format. However, RAW images are going to take up more storage space and will require more postproduction work. Some cameras do have smaller RAW image sizes, which will help to save on storage room.

Full high definition frames are 1920 pixels x 1080 pixels which is the same as a 2 mega pixel file. Even at the smallest JPG settings, your camera is capturing a larger image than this. Therefore, you will be capturing more than enough resolution that will even allow you to add “pan and scan” movements to your final sequence, if you wish. This will allow some additional movement in the frame if you don’t want to resort to more expensive camera sliders or other mechanical movement devices.

I personally prefer capturing RAW images and often set my camera (I use Canon) to the sRAW format, which captures a smaller size frame that is still much larger than 1080p high definition frame. By capturing a RAW image, you have all the advantages of RAW processing, but it will require extra steps after you move your images to your computer. More than likely, your video processing programs may not be able to handle RAW files directly, so you will have to convert them to JPG or TIFF.

I personally use Lightroom to process my first image in the sequence, then copy and paste the develop settings to the rest of the images in the sequence.

As you can see in the following illustration, even the 5D sRAW file is much larger than a full 1920 x 1080 HD video format. Using these larger formats give you the advantage of being able to crop during post­product and even add horizontal, vertical movement or even digital zooms without a loss of quality. The disadvantage is the fact they take up more space on your memory cards!

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File formats compared to HD video

One last tip – if your camera allows you to create folders on the memory card, I like to create a new folder for each sequence, which helps me organize and process my image sequences.

Composition

Finding an appropriate place to put your camera and composing the shot is the same as any good photograph. Keep in mind the rule of thirds and basic composition with the foreground and background framing your subject. Remember that objects in front of the camera will be moving in the frame, so place the camera in a position to accent the movement. It is often better to have the movement coming toward the viewer or going away from the viewer rather than moving straight across the screen. If you are capturing star movement, you will want to point your camera in a northerly direction in the northern hemisphere or toward the south in the southern hemisphere and avoid aiming due east or west. In the north, the stars will rotate around polaris, the north star.

Finally, set your intervalometer and then go read one of our Fotobug guides or listen to our podcast while you wait for the sequence to finish!

Advanced techniques

There is something magical about time­lapse images, but adding camera movement to the capture can make the sequence into something breathtakingly beautiful. Adding movement to the camera isn’t easy and requires some special hardware and software to accomplish. Although you can use the “pan and scan” technique that I wrote about earlier, actually moving the camera is a better technique and has a much better look and feel.

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If you do an Internet search for camera sliders, you will find many versions such as the Igus (www.igus.com ­ also available on Amazon.com) and Glidetrack (www.glidetrack.com). However, you need more than just a track – you need some method to move the camera on the track during or before each frame.

If you are interested in moving the camera, then I highly recommend you check out the open source project from Dynamic Perception (www.dynamicperception.com). They have a track system available for about $900­$1000, but if you don’t mind a little effort, you can save some money by doing it yourself.

The heart of the Dynamic Perception system is the MX2 motion controller. You can buy this pre­made for $225, or you can buy a kit for $55 and build it yourself (you will also need an Arduino microcontroller board for about $20). TheMX2 features free open source software, which will allow you to control up to two motors (such as one for the slider and one for a motorized pan head!) and also acts as a full­featured intervalometer!

MX2 Motion controller

If you want to save yourself even more money, then you will want to check out my camera slider, which uses the Rig Wheels system (www.rigwheels.com). I will be posting the information on my blog and on the Fotobug Facebook page as well as our podcast page at www.thefotobug.com.

The problem with most slider systems is the bulk of the slider. They are difficult and expensive to ship around to various locations. The beauty of my Rig Wheels system is that you only need to pack up the MX2, the camera platform, belt and motor (which can fit in your suitcase) – along with your camera and 2 tripods. Once you arrive at your destination, just buy a couple 1 ¼” PVC pipes or wooden poles (flag poles, garden poles, etc.) and set them up on two tripods and away you go! Once you are done, you just pack up everything but the poles and head to your next destination! The poles should only cost about $15 – 20 and a 10 foot length of 1 ¼” PVC is less than $5.

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In addition to moving the camera along a vertical or horizontal structure, some systems also allow you to add pan and or tilt options to the camera. All of these moves can really enhance your finished video, if done correctly and with a purpose, but it also complicates the setup and capture.

I’ve also read some articles on the Internet about time­lapse photographers who have used motorized Meade Telescope heads modified to accept a camera. These heads allow you to pan and or tilt the camera and could create really interesting moves if combined with a camera slider.

Time­lapse HDR

HDR still photography can produce some amazing images. Imagine taking the HDR technique and apply it to a time­lapse video sequence. Well, many of the intervalometers will allow you to capture multiple frames for HDR capture. Naturally, this complicates your setup. First of all, you want to capture a scene that suits HDR (high contrast scenes). You also need to consider the extra storage for the multiple frames as well as the post processing work. Finally, there will be additional time required to capture all three frames and that time needs to be taken into account, especially if you are doing low­light photography.

For post processing the HDR captures, you will need software that can batch process your HDR frames. Imagine individually processing hundreds of images manually! Most HDR software packages allow you to adjust the first set of captured images, and then apply those same adjustments to the rest of the sequence through batch processing. You then convert the final completed frames into your video sequence.

The “Holy Grail” – sunrises and sunsets

Sunrises and sunsets create a difficult time­lapse situation since the available light changes so dramatically as the sun rises or sets. Due to the difficulty of capturing these events and adjusting to the diminishing or increasing light levels, this capture is known as the “Holy Grail” of time­lapse!

One method to handle the changing light levels is known as bulb ramping. This method gradually increases (or decreases) the shutter exposure time in order to adjust for the changing exposure. There was an Arduino based electronic board sold for a while called the Little Bramper (http://www.thewhippersnapper.com) ­ but at the moment the inventor has stopped building and selling the unit. However, there are other intervalometers sold that offer bulb ramping capability.

Another method is to change the exposure during the sequence by increasing (or decreasing for sunrises) the ISO between two frames when the images are too far underexposed (or overexposed!). This will create a sudden change in exposure levels, but there is a software program called LRTimeLapse (www.lrtimelapse.com) that works with Adobe’s Lightroom that will help smooth out the changes. This program will also smooth out any flicker that may occur in your sequence and I will discuss it more under the section on postproduction.

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The software programGBTimeLapse (http://www.granitebaysoftware.com/) only runs on Windows systems but will also allow you to program in ramping to increase or decrease exposure during the sequence capture. GBTimeLapse has a lot of other capabilities as well, but does require you to take your laptop into the field with you!

A technique, which I haven’t tried yet, but should work, is to set your camera to take bracketed exposures, just like HDR. However, instead of taking an under­exposed image, correct exposure and over­exposed image, set the bracket to take an image one stop over (or more), and another two stops over (or more for sunsets – do the opposite for sunrises). When you go to process your images, select the first range of frames until the exposure on the last frame is too underexposed, then select the next sequence and do the same for the third sequence. You will need a program such as LRTimeLapse to smooth out the exposures, but this would allow you to record up to 4 stops difference and even more if your camera allows more than three bracketed exposures (such as many Nikons and high end Canons).

Star trails

Star trails don’t have to be video sequences of the Milky Way rotating in the sky, but can also be a still image with the movement of the stars creating a streak and circling around the North Star.

As I already indicated, avoid aiming the camera toward the east or west and in the northern hemisphere it is best to aim in a northerly direction and in a southerly direction in the southern hemisphere. The reason for avoiding east/west directions is the fact the stars will streak or move nearly straight up and down. The movement or streaks look much better when they rotate in an arc in your sequence or image.

Light pollution is one of the biggest problems for star trails or night sky photography. You will want to be far from city lights and choose a night of a new moon, or at least when the moon will be below the horizon. You will also want to find a spot with an interesting foreground even though that foreground may only appear as a silhouette and you will need a clear night with few, if any clouds as well as smoke or fog.

Recording star trails presents a number of other challenges. You will be attempting to record faint points of light from a rotating sphere (the earth!) while avoiding high noise levels in your final image. Long exposure times are a given and you will likely need to crank up your ISO levels. A fast lens is also highly recommended!

There is another factor to keep in mind. Since the earth is turning, long exposures can result in the stars appears as streaks and not points of light. Actually a small amount of streaking (motion blur) will result in smoother playback motion and if you desire a final still image with the circular star streaks, then this is not a problem. There is a rule of thumb called the ‘rule of 600’ that will calculate the amount of streaking. Just divide 600 by the effective 35mm focal length of your lens and that is the maximum exposure time to avoid streaks.

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So, if you have an APS­C cropped sensor (1.6x) and a 10mm lens – the 35mm equivalent focal length is 10mm x 1.6 or 16mm. Divide 600 by 16 and you will get 37.5. So, 37.5 seconds should be the maximum shutter exposure to avoid blurring the stars.

However, I wouldn’t be too concerned about streaks for a video sequence and if you want a star trail still image then you want the streaks anyway! For the above example, I wouldn’t hesitate to use a 1­minute exposure, or perhaps even a bit longer.

You may be wondering why I’m discussing a star trail still photo in this section when this guide is about time­lapse sequences. Glad you asked! If you want a long star streak, that would require leaving the camera shutter open for 30 to 40 minutes, minimum, to several hours! This causes a few problems. One is the fact the battery(s) must be capable of providing enough power to keep the shutter open. The other problem is noise. The longer the shutter remains open, the more heat the sensor generates and the more noise that is produced. So, a better method would be to shoot a number of still images of shorter duration for the same 40 minutes to several hour capture time. This is time­lapse photography!

There is an interesting software program called Startrails available at http://www.startrails.de that will take those series of still images and will convert them into a single image with star trails! It can even use one of the images in the sequence as a foreground, in that case you may want to use a longer exposure for the foreground for that frame, or use light­painting techniques to light up the foreground. Also, you can record one image with the lens cap on which will record the natural noise level from the sensor and Startrails will subtract that noise from the final image.

If that isn’t enough, Startrails can even output a video where the stars will start as a point and “grow” into the streaks – a very interesting effect!

Startrails is donation ware and unfortunately, only runs on the Windows platform.

I understand that Helicon Focus (www.heliconsoft.com ) is also capable of putting together individual images to create a star­trail and is available for both the Mac and PC platforms. Helicon Focus was originally created to do focus stacking for macro images.

Star trails and celestial sky time­lapse sequences really come alive when the camera moves in relation to silhouetted objects that appear against the starry sky. In fact, sequences of the stars in the sky rotating behind a giant western cactus, which is silhouetted in the foreground while the camera rotates around it has become almost a time­lapse cliché!

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Startrails application

Post production

After you have gathered all those individual frames, you still have more work to do in order to create a nice video sequence. When you transfer your captured images to your computer, make sure the method you use doesn’t change the file name of each frame. You need the sequence number in order to convert the individual frames into a video sequence.

Cameras do have an upper limit for the sequence number, then it starts back again at zero. It is possible that you could hit this limit (and it will happen sooner or later), which will mean that part of the sequence will have lower numbers than earlier captured frames. You could process the two parts individually, and then assemble them later. However, Granite Bay (www.granitebaysoftware.com) has a free program for Windows called GBResquence that will allow you to renumber all or selected captured images in a folder.

Once all your frames have been copied and numbered, you can import them using your favorite video editing software. Most editing programs allow you to import stills and have an option to import the images as a sequence. Once you have completed this, depending upon your computer hardware and software capabilities, you may have a sequence that you can view directly, or at least export out as a video file.

You don’t necessarily need expensive video editing software to create your video sequence. Virtualdub for windows (http://virtualdub.org/index.html) is a free program that you can use, and Quicktime Pro only costs about $30 and is available for Macs and PCs and will convert individual frames into a video sequence.

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Another interesting option is LRTimeLapse (www.lrtimelapse.com). LRTimeLapse works with Lightroom from Adobe and not only allows you to export your still frames as a video sequence, but also has some interesting techniques that will allow you to reduce, or eliminate any flicker that may occur, and can be used to ramp exposures gradually for the ”Holy Grail” of sunrises and sunsets!

Lightworks (www.lwks.com) is another program available for multiple platforms and is a professional based editing software that has a free version as well as an inexpensive paid version. Lightworks has been used to edit some well­known Hollywood motion pictures and is worth checking out!

If you are attempting an HDR time­lapse sequence, you will have to batch process all your HDR frames with your favorite HDR software before you can import them into your video software and create a video sequence. If your HDR software changes the name of the final output file, you can always use GBResequence to rename them!

Once your individual frames have been converted to a video sequence, you can edit it and treat it exactly like you would any other video sequence. Since your still frames will not be in the same 16:9 format for high definition or 4:3 format for standard definition, you can also add ‘pan and scan’ movement to the final sequence with little, if any loss of quality. The frames that you captured are more than likely much larger than even the 1920 x 1080 pixel frame size of high definition video. Therefore, you can easily crop and even add movement across or up/down the frame to add additional movement to your sequence. This movement may not be as good as the movement captured using a camera slider/dolly/panhead, but perhaps can be used to improve your final sequence.

Warning!

I just want to make you aware that all shutters have a lifespan. The number of actuations will be different for different models and makes. The number could range from 100,000 to 300,000, with 150,000 being the average. This means that at some time, the shutter will be worn out and will have to be replaced. Since time­lapse takes so many frames, recording a lot of time­lapse images will wear the shutter out faster!

Repair costs for the shutter will also be different depending upon the model and make, but my last shutter repair for a Canon 1D MK II N cost $250 a few years back. I’m only including this figure and warning so that you are aware of the issue!

However, you don’t need to use your expensive DSLR for time­lapse! In fact, many digital compact cameras have time­lapse capabilities built­in and as long as they can accept an external shutter release, you can add an intervalometer. Even the little sports camera, the GoPro Hero, has built­in time­lapse capability. There are also apps for iPhone and Android camera phones.

Just keep in mind that the same issues apply to compact digital cameras as they do for DSLR cameras. You still want to use manual mode, aperture wide­open and charged batteries!

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Recap

Here is a summary list of the steps required to capture a time­lapse sequence:

1. Determine your time­base, that is the frame rate that you will be playing back your final sequence (usually 24 or 30 fps).

2. Determine the length of time of the sequence you want to capture. This is optional, but you will likely want at least a 10 second sequence. By using your time­base, you can calculate how long it will take to capture the necessary frames for the sequence length.

3. Decide on the rate that you want to capture. That is, 1 frame every 3 seconds, 1 frame every 30 seconds, etc.

4. Figure out the ISO, shutter speed and aperture for the lighting conditions. Remember that you may wish to drag your shutter a bit in order to introduce some blur into the frames.

5. Put everything on your camera and lens on manual and set your ISO and exposure. Set your white balance.

6. Decide if you are going to capture JPG or RAW images and set your camera accordingly.

7. Frame up your scene keeping in mind good compositional “rules”. 8. Program you intervalometer with the capture rate, number of capture frames

(optional), shutter exposure (if you are using bulb on your camera), etc. Make sure you have enough battery life for your camera and intervalometer and don’t forget to use a memory card with enough storage space.

9. Start everything up, sit back and listen to a Fotobug podcast while you wait for your sequence to be captured!

10. Transfer the frames to your computer, apply any postproduction adjustments and output your final video sequence.

11. Post your video on the Internet and earn fame and accolades!

Most of all have fun and be creative. Sure, sunrises, sunsets, and star movement are awesome and fun to watch, but why not use the same effort to capture something new and interesting? Consider the inflow and outflow of ocean tides, insect colonies, decaying fruit or vegetables, rush­hour patterns, and city nightscapes – use your imagination! Sure, you are going to capture clouds, sunrises and sunsets, so try to find unique interesting angles and viewpoints and for advanced users, and add some interesting camera movement.

Finally, put your time­lapse captured footage into a meaningful and interesting final film, add some original music and a soundtrack and be sure to share your vision with the Fotobug community! Check out some of the examples I’ve listed below for inspiration and search YouTube and Vimeo for more interesting examples.

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Formulas

Number of frames required: Total video length (seconds) x frame rate (fps) = number of frames required. Example: 12 seconds of finished video x 24fps = 288 frames

Total shooting time: Total number of frames x (interval between frames + exposure time in seconds) = Total shooting time required. (Note: exposure time can be ignored if it is relatively short!). Divide by 60 to get number of minutes. Example: 300 frames x 5 seconds = 1500 second. 1500 seconds/60 = 25 minutes

“Ideal” shutter speed (for motion blur): Just under 50% of the frame interval. So, if you are capturing a frame every three seconds, you will likely have the best results with an exposure that is around 1 to 1.5 seconds long to produce the relative amount of blur that matches normal 24fps motion picture blur. This breaks down for very long gaps between frames and you likely want to use no more than a 30 second exposure rate. Consider the amount of motion in the frame. For rapid motion, you can use a faster shutter speed, than you should for slower movement.

Rule of 600:

600 divided by the 35mm equivalent of the focal length of the lens = the maximum shutter exposure in seconds to prevent noticeable star streaks (this includes the moon!). Example: 600/50mm = 12 seconds

Recommended frame intervals (between frames): 1 second – Moving traffic, fast moving clouds, through the windshield drive sequences 1 to 3 seconds – sunrises and sunsets, slow moving clouds, pedestrians, and telephoto time­lapse sequences. 15 seconds and longer – moving landscape shadows, clear sky daylight sun movement, star trails, plant growth, building construction (these may require up to 15 minutes or more between frames!).

These are just guidelines, feel free to experiment!

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Resources

Hardware –

Amazon – www.amazon.com ­ intervalometers, ND filters, books, etc. Link Delight – www.linkdelight.com ­ intervalometers, ND filters, etc Promote Control – www.promotesystems.com ­ high end intervalometer Time­lapse+ ­ www.timelapseplus.com ­ universal intervaolometer Time Machine – www.bmumford.com ­ high­end intervalometer Trigger Trap – www.triggertrap.com ­ kit and pre­built intervalometer and mobile

version IOShutter – www.enlightphotopro.com ­ Mobile intervalometer DSLR Remote – www.ononesoftware.com ­ intervalometer Dolly Shield – www.dynamicperception.com ­ intervalometer and motor controller Igus – www.igus.com ­ camera slider track Glidetrack – www.glidetrack.com ­ camera slider track Rig Wheels – www.rigwheels.com ­ Rig wheel camera slider hardware

Software –

LRTimeLapse – www.lrtimelapse.com ­ PC software – assembles images GBTimeLapse – www.granitebaysoftware.com ­ PC software – multiple capabilities Startrails – www.startrails.de ­ PC software – assembles images Helicon Focus – www.heliconsoft.com ­ PC & Mac – assembles images GBReSequence – www.granitebaysoftware.com ­ PC software – renumbers images Virtual Dub – http://virtualdub.org/ ­ PC software editor Quicktime Pro – www.quicktime.com ­ PC and Mac – limited video editing Lightworks – www.lwks.com ­ multiple platforms – editing software, free and paid FFMPEG ­ http://ffmpeg.org/ ­ free multiple platform program to assemble images

Misc – CHDK – http://chdk.wikia.com/wiki/CHDK ­ hacked firmware for Canon cameras

allows timelapse, and is free, use with http://chdk.wikia.com/wiki/UBASIC/Scripts:_OMNI_Intervalometer

Publications –

Time Lapse Shooting and Processing – Gunther Wegner ­ www.timelapse.com/shop/ebook Time­lapse Photography ­ Ryan Chylinksi ­ www.learntimelapse.com/time­lapse­photography­book/

Time­lapse videos –

Baltic Skies ­ http://vimeo.com/25664076 Alpine Skies ­ http://vimeo.com/29678004 Canary Skies ­ http://vimeo.com/35475716 Time­lapse The City Limits ­ http://vimeo.com/23237102 Landscapes – Vol 2 ­ http://vimeo.com/29950141 ­ (HDR time­lapse)

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We hope you enjoyed this free guide and hopefully it will help you get started creating your own time­lapse videos. If you have any questions, don’t hesitate to contact us and please continue to tune in to our bi­weekly podcasts at www.thefotobug.com ­ or better yet, via one of the major podcast feeds such as iTunes, Zune, or Miro! You can also return the favor to us by leaving us some feedback on iTunes, (or Miro, or even at our website, www.thefotobug.com). We are also on Facebook and would love for you to ‘Like’ us!

You may also want to check out our other photo guides. There are more to come!

2012 Jim Caldwell

Authored by Jim Caldwell – www.thefotobug.com jim.fotobug@verizon.net