Doublespeak

On my recent trip to Yellowstone, I recorded a time-lapse video of the complete road trip using a point&shoot. However, the Canon P&S cameras that have this capability can only record standard-definition time-lapses. For higher quality time-lapses I had to resort to my DSLR. Here’s how I did it:

Step 1: Get your equipment

You will need a good tripod, especially if you shoot in windy places with a heavy lens attached to your camera. I use Manfrotto 055x legs along with a 322RC2 quick-release ball-head. It’s an expensive setup, but a sturdy tripod is one of the best investments you can make in photography.

You will also need a remote shutter release that allows you to set a periodic rate for your image captures. I have a cheap brand-less timer remote I found on Amazon that works great and allows me to program in pretty much any interval between my images. Make sure you understand how to program it before you go out on the field.

Step 2: Capture your time-lapse sequence

Capturing your sequence is as simple as shooting images at a periodic rate. However, there are a few things that are worth keeping in mind.

• Size: Remember that the highest resolution for a 720p movie will be 1280×720, so for most DSLRs, even the smallest image size setting will be more than sufficient. If you shoot large images, not only will it be a waste of space, you will also find it painful to render a movie. (There’s one situation where you might want to shoot a larger movie though – if you want to do a pan/zoom in your video afterwards, it will be helpful to have more image data to work with).
• Focus: Also ensure that you have all your settings in manual mode so that things don’t change from frame-to-frame. You can also save some battery by focusing once and then putting your lens in manual-focus mode for the remainder of the shoot. (I usually shoot a few test images when I change scenes so that I can easily identify blocks of images by looking for a gap in the file-names. Of course, if you are using software such as Lightroom, you can just stack your images based on the interval between captures)
• Camera Settings: Most of the camera settings are better left in automatic mode. For example, if you are shooting a sunset, your exposure needs will change very quickly over time, so unless you are shooting raw, you are better off letting the camera choose the best exposure. If you manually change the exposure in the middle of the capture, the change in exposure will be very evident in the movie. However, there’s one setting that’s better not left in auto mode – White Balance.
• Timing: While calculating how many images to shoot, start with the framerate you will use for your movie. If you plan to stitch the images into a movie at 24fps, then you would need 24*10=240 images to generate a 10s movie. It’s important to plan how many images you will want, otherwise you may end up with a clip that’s either too short to be used, or has to use a slower framerate in order to be long enough.

Step 3: Stitch your images in to a movie

This is the tricky part. There are many ways to do this, but not all of them are easy to use. If you are on Windows, you can use Windows Movie Maker (and if you are on a Mac, you can simply use iMovie). Both these tools have one big limitation – they are not designed for stop-motion or time-lapses, so you can’t easily choose the frames-per-second for your movie. Instead you would have to calculate the duration of each frame (1/fps) and use the approximate number you get.

On a Mac, it is possible to use QuickTime Pro to directly open an image sequence and stitch it into a movie while specifying the fps. However on Snow Leopard, you get QuickTime X which still doesn’t have this functionality. There are ways to install QuickTime Pro alongside QuickTime X, but let’s not go into that. One of the easiest solutions I found is a script that someone wrote which uses the same functionality from QuickTime. Download this script and extract the app into a folder. When you run it, you will be asked to choose the images you want to convert to a movie. I usually put all the images for a time-lapse in a single folders so that I can select them all. You can then choose whether you want to do frames-per-second or seconds-per-frame. I usually choose frames-per-second (15fps) – you can always speed up or slow down the movie later in some movie editing software (iMovie or Final Cut). Finally say yes when it asks you whether the images should be sorted by file-name.

That’s it! You will get a .mov file with your time-lapse in it. There’s one final step though – your movie will have a frame that’s larger than you need since your images are larger than hi-def. Import this movie file into any movie-editor (I prefer iMovie, but Final Cut Express will give you a bit more functionality if you choose to figure it out) and render it as a 720p movie. You will also get a chance to change the speed of the movie at this stage.

Bonus: How to do a pan-zoom within your movie
The fancier time-lapse movies have pans that add more dynamism to the movies. This is best accomplished using motorized rails so that you can physically move the camera while shooting. However an el-cheapo way of doing this is to use your larger-than-HD movie and simply pan and zoom within that movie frame itself. It won’t be the same as a physical pan but you will instantly change the feel of the complete movie. Unfortunately I haven’t found any way to animate movies within iMovie, but Final Cut Express (or Pro) will do this relatively easily.

Have fun making your time-lapses! My time-lapse video from my visit to Yellowstone and Glacier National Parks is at the top of this post.