CompuServe Thread

#Frame Rate

5 messages in this thread
#44125From: Bruce R. MatthewsNov 1, 1994 9:24 AM
As I recall, film animation such as Disney was filmed at a 24 fps rate. However, to smoothen the animations for the human eye, most animations were filmed in two's, that is, each cel was exposed twice. This would give an effective rate of 12 fps, though the actual cells were zooming by at 24 fps. Now enter my trusty Amiga. I too want smooth animations "filmed" in two's, and put out to video tape. Thus, an effective rate of say, 15 fps, but playing at an overall rate of 30 fps. Unfortunately, maintaining a 30 fps rate is quite difficult, even with an A4000. But as I think about it, perhaps a 30 fps rate is not neccessary when outputting to video. If I play my animations at 15 fps, and I genlock to video running (NTSC) at 30 fps, then wouldn't the video automatically record the animations in two's? I reason if it's playing at 15 fps, then each cell will be displayed during two frames of video (okay, so it's actually recorded in 4's since each frame is comprised of two fields). Thus, sustaining a 30 fps rate on the Amiga wouldn't be neccessary. Is this line of reasoning okay, or is there a flaw in it? Any comments? Bruce
#44137From: James R. OllickNov 1, 1994 7:32 PM
You are correct, the VCR will record at 30 frames (60 fields) per second. Therefore if you play your animation at 10 fps you will see 3 frames on playback that are the same, 2 for 15 fps. The animation may still look jerky though, you will just have to experiment. Keep in mind that if the animation looks jerky when playing it on your Amiga, it will be recorded and played back with the same jerkeyness. Jim R. Ollick Using AP from Bergenfield, NJ
#44347From: Bruce R. MatthewsNov 15, 1994 1:26 PM
Hi Jim, >>You are correct, the VCR will record at 30 frames (60 fields) per second. >>Therefore if you play your animation at 10 fps you will see 3 frames on >>playback that are the same, 2 for 15 fps. The animation may still look >>jerky though, you will just have to experiment. Keep in mind that if the >>animation looks jerky when playing it on your Amiga, it will be recorded >>and played back with the same jerkeyness. HHmm, okay. I'm still puzzled about something though. Why is it that film cartoons can appear smooth when filmed in two's at a 24 fps rate, yet look jerky on the computer when I try the same thing? Could it be not enough artificial blurring in my animations or not enough tweens (though too many tweens slow it down at times). Or is it all of the above and then some? Sigh, … I know, I know, more experimenting <g>. Bruce
#44349From: James R. OllickNov 15, 1994 8:42 PM
I have never heard of film being only 12 actual frames filmed twice. A rate of change between pictures of only 12 per second will appear jerky no matter how many times the same picture is duplicated. Jim R. Ollick Using AP from Bergenfield, NJ
#44364From: Peter GreciNov 17, 1994 5:42 PM
PMFJI most Disney Animated features are "Shot on Two's" Except for scenes involving ALOT of motion. This is from a book I have entitled "Disney Animation:The Illusion of Life" Shotr on Two's means theres really only 12 drawings for every second of animation and they shoot each frame twice to make the 24 FPS Memeber of AMP Midgard Graphics