Figuring Out Time Lapse Photography

Inspired by Philip Bloom, and many other renowned DSLR cinematographers, I decided to purchase and intervalometer, and give Time Lapse photography a shot. Using the affordable and simple to use, Aputure Intervalometer, I've run a few time lapses to try and figure out the best camera settings. Here are the results so far.

This first time lapse was recorded looking out over the Hudson River from Northern New Jersey. I used my Canon Rebel T2i, set to AV mode (Aperture Priority) with the intervalometer set to capture a 2 second exposure every 1 second. Because it was simply a test, and I am impatient, I only left the camera running for about 30 minutes. You can see me jumping through the frame checking the camera, as I wasn't really sure what I was doing. For a first time lapse, it didn't come out too bad. You'll have to excuse the quality, as I just uploaded the Quick Time videos for the sake of this blog posting. Once I get the hang of it, I'll post a proper video.

This Time Lapse was recorded from my window in Greenwhich Village. Again, I set the T2i to AV mode, and the Intervalometer to take a 2 second exposure every 1 second. However, because it was a night time shot, the camera automatically changed the exposure speed to compensate, so in reality, it was closer to a 4 or 5 second exposure per picture. The flickering green light is the faulty street light outside my window, and not an effect of the time lapse. Neither of the above videos were color corrected or edited in any way.

I definitely need some more practice, but here are my thoughts so far.

1. Knowing your math is important. How long you leave the camera snapping photos will depend on how long you want the final time lapse to be. Here's a quick example. If you want a 10 second time lapse, at 24 frames per second you will need to take 240 pictures. If the exposure of each picture is 2 seconds, you will need to wait 480 seconds, or 8 minutes. Doing the math will help you use your time more effectively.
2. Different exposure times give different effects. Short exposure times seem to give a more choppy look to the footage, where as longer exposures give a smoother dream like look. Then again, this will also vary based on what your shooting. If an object is moving quickly, a fast exposure may be the only way to capture it.
3. AV mode has it's ups and downs. Currently, AV mode is the best way to control photo exposure on the Canon DSLRs. It's only draw back would seem to be that it will automatically change your exposure time, despite what you set your intervalometer to. This means calculations discussed above may be useless as exposure times may change mid shoot. That being said, AV mode readjusting shutter speeds will most likely save a time lapse from being ruined by an overly dark, or overly light photo in the sequence.
4. Practice and Patience are key. Philip Bloom makes time lapses look easy, but in reality, there seems to be a lot of luck in making them look good. With enough patience and practice, you should begin to understand how to get consistently good shoots, but because lighting conditions are always subject to change over time, it's a bit of a coin toss.

As I get more comfortable shooting time lapse, I'll post some tips and guides I find useful. However, at this point, I'm still figuring things out.