Thank you for yur quick reply. My movie was shot in 30 fps, why should I change the frame rate to 59.94 ?
My movie was shot in 30 fps
Depends. There are cameras that always shoot 60fps and then tag the streams to produce otehr frame rates by suppressing inbetween frames and require proper settings for the faux pulldown. Also give some consideration to settings for fields. No matter what it is, it's probably easily solved by setting your footage interpretation correctly, which so far you haven't.
It is as Mylenium says. If your camera shoots 30 frames per second (actually 29.97), then it's really shooting 59.94 fields per second.
The best way to make sure that your composition is set up correctly is to create your composition by dragging your footage item to the Create A New Composition button at the bottom of the Project panel. Then, you're guaranteed that the frame rates will match.
That message in the Info panel that tells you that a RAM preview is not playing in real time is not an error, per se. It's just telling you that your computer isn't capable of playing that many frames per second back to the screen. If you need real-time RAM preview, then there are all sorts of other things that you can do, such as using a region of interest to only preview a specific area of the frames. There are many tips for increasing performance of RAM previews here.
In general, if you're expecting things in After Effects to be real-time without making tradeoffs, then you're expecting the wrong thing.
I have HP 64, Window 7 with 9 Gig of Ram, 2 Gig HD.
After Effects is not designed as a realtime playback application. It is quite usual to RAM preview your comps (keying 0 on the keypad). This loads the comp into memory and then attempts to play back in realtime.
The duration of the RAM preview depends upon how much RAM you have together with the complexity of the composition - to name but two.
There are several ways to optimise RAM preview efficiency - such as preview resolution; Shift Preview: work bar coverage; etc, etc.
You have a point with the frame rate mis-match. I have some SD footage on a Sony 570 which I know to be PAL 720 x 576 interlaced 25 FPS. If I drag it onto the new comp icon, AE CS5 correctly creates a new comp at 25 FPS lower field. However, Roto Brush also tells me that I have a frame rate mis-match and that I need to adjust the comp to 50 FPS. This message vanishes once I've done as I'm told, but the footage is not 50 FPS - interlaced or non- interlaced.
Any futher thoughts anyone?
Todd, Mylenium, any views on this? I have read the Roto Brush frame rate guidance, but it still doesn't put this issue to bed!
"I have some SD footage on a Sony 570 which I know to be PAL 720 x 576 interlaced 25 FPS. If I drag it onto the new comp icon, AE CS5 correctly creates a new comp at 25 FPS lower field. However, Roto Brush also tells me that I have a frame rate mis-match and that I need to adjust the comp to 50 FPS. This message vanishes once I've done as I'm told, but the footage is not 50 FPS - interlaced or non- interlaced."