FPS and NFD in AE

[twonew82]

Hello, Me and my friend recently started playing around with creating digital media, art, etc. He recently got Ae to aid us in this. Which is a phenomenal software BTW. Especially with the plug-ins I have found from adobe and co-pilot. Although I am pretty knowledgeable when it comes to computers, I am fairly ignorant when it comes to all things video related. We have been creating a still frame animation. I have been having trouble with the frame rate, because some frames need a slower and some faster due to me not understanding frame rate during creation of said frames. However my question is about DF and NDF. Firstly, At one point I had the first part at 25 fps and ndf, but now after some very light editing and testing other FPS options when I choose 25fps ndf is not an option. What would cause ndf to be or not be available. Also on another part where I have less transition images I need to drop down to a much slower frame rate but when I do this it keeps skipping frames. When I bring up the FPS to a rate it allows me to choose ndf it plays the frames but it's too fast. I thought NDF wasn't supposed to actually drop frames. Only affect the way it kept track of them. That's what I have read anyway. So I am a little confused. Any assistance to help me understand this would be greatly appreciated. Thanks for taking the time to read this even if you do not have the solution, have a great everything.

[twonew82]

I guess I can't edit my own post, that's inconvenient! I meant thought DF wasn't supposed to actually drop frames. Small error , but just like to correect my errors. Thanks!

[Warren Heaton]

Drop Frame Time Code (DFTC) and Non-Drop Frame Time Code (NDFTC) only apply if you're working at 29.97 frames per second.

With DFTC, the numbering of the frames skips ahead at regular intervals while the number of frames played per second remains the same.  Specifically, the time stamp (or time code) of the frames skips ahead two frames each minute except for every tenth minute to keep time with a real world clock.  Even though no frames are actually removed, the professional term is "drop".  I guess it's better than "two frame numbers skip ahead" time code.

We can see this at work in After Effects if we create two Compositions that are 11 minutes or longer: one at 29.97 Drop and the other at 29.97 Non-Drop.  Anything longer than one minute is long enough to see the renumbering (or the drop), but it's not long enough to see the "except every 10th minute" part.

What's nice about After Effects is that the Time Display in the Timeline panel shows the frame number below the Time Code, assuming we have not used command-click, Mac or control-click, Windows to reverse the display.

As we advance though the 29.97 Drop Frame Comp, we'll see the 0;00;59;29 time code at frame 1799 skip ahead to 0;01;00;02 when we advance to the next frame 1,800.  As such, our numbering has skipped ahead two frames - or two frames are dropped - while we've gone to the next frame.  When we get to 0:09:59:29, it continues to 0:10:00:00 and we are at frame 17,982.  Accordinly, it takes us less time to get to ten minutes than with Non-Drop Frame Time Code.  For broadcast and cable anywhere video runs at 29.97, we have to use Drop Frame Time Code.

As we advance through the 29.97 Non-Drop Frame Comp, we'll see the 0;00;59;29 time code at frame 1799 continue to 0:01:00:00 when we advance to the next frame 1,800.   The numbering has not skipped ahead (or no frame have been dropped).  When we get to 0:09:59:29, it continues to 0:10:00:00 and we are at frame 18,000.  Accordinly, it takes us longer to get to ten minutes with Drop Frame Time Code.

In your post, you talk about needing some things to go slower or faster.  You'd most likely achieve this in After Effects with how you implement Temporal Keyframe Interpolation, but Time Remapping is another method to look into.