Time-Lapse Photography vs. Sped-up video??? Intriguing.....

y2kwizard · Post by **y2kwizard** » Thu Sep 26, 2002 9:04 pm

Hello all. I've been wondering how best to do a time-lapse sequence of my high school stadium filling up with people, and i'm looking for some advice. I'm sure this technique can also be used in terms of Anime.

OK, so my main question is this: what's the difference between timelapse photography and simlpy speeding up a loooong video segment? I mean, I know timelapse is PHOTOGRAPHY, where a still camera is set up to take a picture once every few minutes or something, and that speeding up video requires a lot of tapes, batteries, etc. to do.

So can I get the same results with timelapse as I do with setting up a video camera? I mean, when you speed up video footage, Premiere or whatever program you're using just drops frames to get the speed up, and time-lapse photography seems to "drop" frames because it selectively picks a frame every second or two. Let's look at it mathematically:

Let's make this easy. Let's say I want to make an hour's worth of footage condensed into 2 seconds. Let's also say, just for simplicity, that NTSC video runs at 30 FPS rather than 29.97

Time Lapse: To do this, I must set the camera to take a picture once every minute: 60 minutes in an hour means 60 pictures at 30 FPS means 2 seconds of footage. 60 pictures * 30 FPS is 1800...this means that if this were video I'd be taking one picture out of every 1800 possible pictures.

Videotape: I take 30 framesx60 secondsx60 minutes = 108000 frames of footage with the video tape. However, if I want to get 2 seconds of footage, I need to bring that down to 60 frames of footage. If I divide 108000 by 60 I get 1800 frames, meaning I take one frame out of every 1800 frames..... just the same as the time lapse photography!!!

SO would these look any different? Does anyone know?

Thanks a lot, guys!!

alternatefutures · Post by **alternatefutures** » Thu Sep 26, 2002 10:15 pm

Well, if you want to do the timelapse over, say, a day, then there's no question you'd have to go with a still camera because you wouldn't have enough tape to cover the time span, and once you touch the video camera you've just jarred the image. Even if you want to do it over the span of a few hours the still camera is better simply because of the ammount of time it would take for you to record/digitize the video footage. However, the end result of either method is the same.

Mask of Destiny · Post by **Mask of Destiny** » Thu Sep 26, 2002 10:52 pm

Well the only problems from a quality point of view with the video camera aproach are resolution and interlacing. Generally speaking, any kind of still camera has a higher resolution than a video camera, but I doubt you need enough resolution for this to matter. Interlacing isn't a big problem as long as you use the proper filters. If that doesn't work you can always take it at half-vertical resolution.

hackerzc · Post by **hackerzc** » Tue Oct 08, 2002 11:31 pm

Weather you use Time laps or cange the speed, it will turn out the same. In fact the Speed up might turn out even better. The only problem is that when you go to digitize the video footage, it will take up alot of space.

So the real question is, do you have the HDD space to do a 60minute capture at the quality and compression you want to use? If the answer is no, then time-laps is the way to go.