I'm confused about frame rates. I make short animated films and I'd like my animation to look as smooth and beautiful as possible. I use a variety of source material: drawings, photos, particle generators, etc. Should I be building my shorts at 23.976 or 29.97 or something else entirely? And what's the difference between "i" and "p". I guess they stand for interpolated and progressive, but how does this affect the outcome? Thanks. Ellen
Thank you Stephen. I do like the film look. Although, I wonder if I can really tell the difference ––– I even have an MFA in film, given back in the days when film and video had nothing to do with each other.
So now can you tell me what fields are? Also, I've heard that faster frame rates can give you smoother animation. Is this true?
Sorry for the delayed response, I've been buried knee deep in work. To answer your question.
Interlaced video is a scanning method that divides a video frame into two fields, each consisting of alternating odd and even lines that are scanned at different times. When those two fields are put together you have what you see in a frame.
A progressive scan just scans all of the lines consecutively.
Frame rates lower than 40 fps can cause noticeable flicker. When NTSC and PAL were invented, faster frame rates were not practical to implement. Interlaced scanning was devised to create a perceived frame rate of 60 fps (NTSC) or 50 fps (PAL). Interlaced video scans the display twice, using two fields, to complete a single frame. A single field contains only the odd lines (1, 3, 5, 7, and so on) or the even lines (2, 4, 6, 8, and so on) of the frame. If you could stop the video scanning process to observe a single video field, you would see that every other line is missing, like venetian blinds or a comb.
Because the fields are changing at twice the frame rate, there is less perceived flicker than if each frame was scanned progressively. For example, with NTSC, a field of odd lines is scanned in 1/60 of a second and a field of even lines follows in the next 1/60 of a second, resulting in a complete frame every 1/30 of a second. Take a look at the image below:
As for frame rates, I recommend you play around with some different frame rates and see what you like. For a documentary I'm working on that is 24p we decided to make the animations 30fps for a smother look.