Thursday, 4 March 2010

Making a Time Lapse Movie

Time lapse is a movie making technique where time appears to be compressed or made shorter. For example a whole 24 hour day into 24 seconds on screen! This article is intended to give DSLR photographers to knowledge to begin the process of creating time lapse movies with their DSLR camera by shooting a series of still frames and combining them in Adobe Photoshop or Apple Quicktime Pro.


A time lapse movie need not be a single shot with the camera locked-off for the whole movie. With some planning and forethought you can combine real-time footage with time lapse sequences to great effect. The movie below was created over two days. It starts and finishes with real-time footage shot with a Canon 5D Mk II outside at the beginning and a Canon 7D inside at the end. The intervening time lapse sequences were shot at around one frame every 20 seconds. There were one or two sequences where this frame rate was reduced to one frame every five seconds where the action happened much quicker.






At first time lapse shooting can be quite daunting, but like any photography or cine/video photography, practice will build your confidence. What I intend to do here is share with you the whole process from start to finish covering everything from equipment, frame rate and conversion to a simple movie clip.


Equipment

Contrary to popular belief you do not need a DSLR with a video facility to make a movie. A movie is simply a series of still frames combined to create a moving image file such as .mov (Mac) or .avi (PC). If you’re using a Canon DSLR (like me) you’ll need a TC 80 N3 remote release or On One Software’s DSLR Remote with your camera tethered to your MacBook or PC laptop. For ease of use and portability, I generally use the TC 80 N3 remote release with a Canon 50D. For Nikon users the D3 D300, D300s, D5000, D3x, D90 and D700 all have a built-in interval timer. For other Nikon DSLR cameras the Timer Remote MC-36 is available.


File Size

Yes, size is important. For standard stills photography you’ll no doubt be shooting RAW files and jpeg files at the largest size possible in your camera to obtain the best quality images, which means not many images to your memory cards. For video the maximum resolution you’ll need is 1920 pixels x 1080 pixels. So you’ll need to go into your camera menu and select a jpeg file size equal to or slightly larger than this. With the Canon EOS 50 D I use 2352 x 1568* pixels and shoot jpeg only, unless the situation demands RAW capture or you have high capacity memory cards. Invariably you’ll need to crop the image as the aspect ratio (shape) of the DSLR frame is approximately 3:2, whereas the HD TV frame is 16:9 - which means you loose a bit at the top and bottom of the frame. For those of you who use a Canon 5D Mk II or 7D you’ll see in video mode that the top and bottom of the LiveView screen is darkened to show this. You may want to mark your LiveView screen with a chinagraph pencil to show this crop for time lapse shooting.


Remember you’ll not be able to see how many frames are available to you as the frame counter on most DSLR cameras only goes to 999. The easy way to calculate the available number of frames is to put a clean low capacity (512 Mb) memory card in you camera and set the file size and ISO, then see what the top plate LCD shows. On this basis with the Canon 50D I can get around 272 jpeg files on to a 512 Mb CF card at 100 ISO. Sometimes more, depending on the subject matter. So, with one of my 2Gb CF cards I can expect to store around about 1088 jpeg files of 2352 x 1568 pixels. Or 43.5 seconds of finished time lapse sequence at 25 fps.


Camera Settings

This is the bit where your experience comes into play! Sorry, this is not a basic camera setting tutorial. You need to make a decision based upon the situation you’re shooting, the local lighting and the look or effect you want to achieve. If you are confident to using manual exposure, this could be a good choice for clouds moving over a landscape. Av or aperture value maybe a good choice if you’re aiming for a shallow or deep DoF effect. This choice is down to you.


Use manual focus where possible so that the autofocus doesn’t “hunt” for a point of focus if the subject is continually moving. You don’t want focus differences between frames!


Frame Rate or Shooting Interval

This can depend on a number of factors such as the duration of the scene, event you’re filming or the duration of the final clip or piece.


In the UK and Europe TV and motion picture frame rates are around 25 fps (frames per second). Whilst in the US 30 fps is the norm. Motion picture film runs at 24 fps. So, at 25 fps, one minute of on screen time is equal to 1,500 frames.


The sequence below was shot at approximately one frame every 1.5 seconds and lasts 2 seconds or 50 frames. The less frames per minute you shoot the more pronounced the effect will be. Initially, most photographers aren’t too concerned about how long the time lapse sequence is, just so long as they capture something. Do remember it’s better to shoot too many, than too few frames. You can always remove frames from the sequence for a different look and feel later on. REMEMBER that creating a time lapse sequence is not a quick process, so be prepared to hang around for some time!


Here’s a quick example of the calculations of frame rate for a 15 second sequence, shot over one hour: 15 seconds = 375 frames; 1 hour = 3,600 seconds; 3600/375=9.6 or 1 frame every 9.6 seconds. I’d err on the side of caution and shoot a frame every 8 seconds.


Creating the Time Lapse Image Sequence

In order to create the movie sequence you need to combine the individual frames in either Adobe Photoshop or Apple Quicktime Pro.


Adobe Photoshop

Download all you image files into one folder per sequence (it makes managing the clips easier later on). Go to File > Open > and select the folder with the images for the sequence. Select the first image in the sequence. At the bottom of the dialogue there is a tick box “Image Sequence”, make sure you check this box. Then click Open. You’ll then see a dialogue where you set the frame rate. For the UK & Europe 25 fps, US 30 fps.


Save the image sequence first as a PSD file, this gives you a master file which you can return to and edit at a later date. You can view your sequence in Photoshop by opening the Animation dialogue accessed from the Window menu at the top of the page.


To make your movie file go to File > Export > Render Video . . . where you’ll be presented with a series of options. For now stay with the defaults. This article is about getting basic time lapse sequence, not the technicalities of video formats etc. The movie may take a while to render, depending on the specification of your computer.






Apple Quicktime Pro

Again, you’ll need all your images for the time lapse sequence in one folder. Go to File > Open Image Sequence and select the first file in the folder, the click Open. You’ll then see a dialogue. For this exercise choose 25 fps. There are plenty of other options to play with at your leisure. It’s worth experimenting with the different frame rates to see they affect your sequence.


The sequence will then open and in probability exceed the size of your screen. This is because the dimensions of the movie file exceed the pixel dimensions required for TV formats. To fit the movie to your screen hit cmd + 3. To save the movie go to File > Save As . . . create a file name and make sure you’ve selected the “Save as a self-contained movie” button. Your time lapse sequence is now ready to view or edit with the video editing package of your choice.





The movie at the beginning of this article was edited with Apple iMovie ’08 on a 13” MacBook Pro. On a PC I wouldn’t recommend using Windows Movie Maker, but suggest you invest in Adobe’s Premier Elements 8, which unfortunately is not available for the Mac.


This sequence was then cut together with others to create the short movie below.




Time Lapse Sequence Ideas

Any subject where there is change or movement.

  • Moving clouds
  • Waves crashing on a beach
  • Crowded streets
  • Traffic moving - you could combine this with slow shutter speeds to create a blur effect.
  • Plants growing. Quite easy in controlled conditions. Just remember your camera will be out of use for other projects for days or weeks.
  • A building site or development.
  • Start lit sky. A tricky one where there’s heavy light pollution.
  • Transit of the moon.
  • A car or cycle journey

As with any photographic or cinematic technique. You need to practice, practice, practice to perfect the skill. Don’t forget to make copious notes that you can refer back to when something goes right or wrong!


Time Lapse Shooting Check List

  • Camera & Lens
  • Tripod or other camera mounting device
  • Interval timer remote release
  • Camera settings - ISO, Exposure, White Balance, File Size, Focus
  • Spare batteries or mains power supply. As a rule of thumb, I get approximately 2 hours continuous shooting from a Canon 50D or 5D MkII battery at normal temperatures, say 20 degrees Celcius/68 degrees Farenheit
  • Spare memory cards and some way to back them up if you're in for a long session


And finally, one of the best examples of a movie created using a Canon 5D MkII DSLR. I’ll not say anything about this one. You can make your own judgements.


Death Cab for Cutie - Little Bribes from Ross Ching on Vimeo.

Enjoy your movie making.


Ian


* 2352 x 1568 pixels far exceeds the 1920 x 1080 pixels required for HD TV. You’ll have to crop your PSD file down to 1920 x 1080 pixels at 72 dpi in Photoshop to get a workable file size.

4 comments:

  1. Thank you for all of this helpful information. i have just bought the EOS 5d Mk2 and am hoping to do some Time Lapse stuff with it.

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  2. This was fabulous! learned tons..just shot my first cloud timelapse...all I can say is:

    Remember:
    First Clean your lens
    xo

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  3. I'm struggling to get my timelapse remote to trigger my 5dmk2. i feel stupid! what are the camera settings i need to make it work?
    many thanks.

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  4. Very good! Cant wait to make my own timelapse!

    ReplyDelete