Need help to determine the best way to make a time lapse video

[snafubaby]

I want to make a time-lapse video. I don't want motion blur. I want somewhat slower motion for the subjects I'm recording. Here is an example from YouTube of the type of motion I want.


www.youtube.com/watch?v=Nb5GpV_LUuU&HD=1

As you can see, the people at the Coachilla festival are walking fast in this time-lapse video, but not tooo fast. They are walking at a good pace. Could someone help me figure out the interval, playback rate, etc. Of this video? I'd appreciate it!

Thanks!

[budwzr]

About 5 frames per sec., more or less. It's either undercranked, or they had an intervalometer function in their camera.

[fvisagie]

What you want to do is called frame rate decimation. It reduces the number of frames by the specified factor, outputing the remainder at the original frame rate. This perceptually speeds up motion. For what you want here a factor from 2 to 5 will probably work.

Various tools have their own ways of doing this. In VirtualDub:

• decide on a decimation factor
• navigate to Video > Frame Rate
• In 'No change (current: mm.nnn fps)' note the current frame rate mm.nnn
• click 'Change frame rate to (fps)' and enter a value = current x factor, e.g. 25 x 5 = 125
• click 'Decimate by' and enter your factor, e.g. 5
• (To leave video and audio quality unchanged) select Video > Direct stream copy and Audio > Direct stream copy
• Save the result with File > Save as AVI

In this example, 'Change frame rate to (fps)' = 125 sets input (and initial output) frame rate to 125, and 'Decimate by' = 5 reduces both frame count and output frame rate to 1/5 their previous values, i.e. 1/5 the source frames at 25 fps. This then effectively speeds up motion 5 times. See the attachment (I'm having trouble with in-line images today).

The same approach works with other tools, too, although the commands will differ of course.

Cheers,
Francois