Film Speed

[sjpro]

I have been exporting my Retro-8 scans as image sequences. This works great if I shoot at 24fps and edit in a 24fps timeline. If I import an 18fps image sequence into a 24fps timeline, everything is sped up a bit. I have been slowing the footage down to about 71% for "normal" speed. My question: What is the exact speed that I should be applying? Lets say I have 18fps super 8 sound footage and sent the reels off somewhere to get the sound transferred and I scanned the film myself and wanted to sync it with the sound. How much should the 18fps footage be slowed down to run properly in a 24fps timeline?

Thanks

[carllooper]

If the timeline is configured for 24fps, the answer is to slow your 18fps source speed down to :

18/24 * 100% = 75%

Or what amounts to the same result: you would lengthen the duration of (time stretch) the footage to:

24/18 * 100% = 133.33%

In some NLEs you can specify the frame rate at which the source footage was shot. For example in After Effects there is an option to "interpret footage", so using this you would specify the frame rate of your source footage as 18fps, and the system would do the correct calculation for whatever timeline frame rate you are using. For internet delivery you might have, for example, a timeline frame rate of 30 rather than 24. Indeed you could specify a timeline rate of 18 fps in which case there is no speed correction (or duration correction).

Here's another example. Your timeline is configured for 30 fps and your source was shot at 18 fps, so you'll want to slow your source speed down to:

18/30 * 100% = 60%

or what is otherwise the same thing: lengthen the duration of (time stretch) the footage to:

30/18 * 100% = 166.66%

C