Optimal frames per second for digital output

[Anim8tor Cathy]

Many of the books I have on animation talk about 24 FPS – but I realize these books were written when animation was made for film. 30 FPS is the video standard, but it almost feels like over-kill for traditional animation. 15 FPS and under simply looks horrible to me.

What is the optimal FPS for digital delivery that displays good fluidity of motion? Is it still 24 FPS, regardless of whether one is considering film or not?

[Paul Fierlinger]

Much of this depends on your personal taste and style of animation. First, take into account that most animators in the world today, including the Disney studio ones, animate in two's. This means that to animate at 24 fps you set your TVP configuration to 12 fps and animate single frames. Only when you export your project do you change the Frame Rate to 24fps and every image will be automatically doubled in the render process.

This means that if you want to have relatively smooth motion for TV and other video outlets, you should draw at 15fps. Some people will even animate at 10fps and convert to 30fps when rendering out... this works well if you intend to play your film on the Internet as a tiny clip and you can keep it at 10fps and to put it on a DVD to play on your TV set you convert it to 30 fps. It may look slightly jerky, but perfectly suitable for a simple drawing style and it requires a lot less drawings to be made.

I animate at 24fps because my target is 35 mm film so I am working with film speed. But you can also animate at 12 fps and export as 30fps and TVPaint will do the math for you, making some frames repeat themselves twice, a few 3 times. The difference in the result of this conversion between drawing at 15 fps or 12 fps but exporting either of these to 30 fps is mostly in the eye of the beholder.

You will have to find your own choice through time and experience. My advice to you, and there will be those who will disagree, is to animate in 12 fps projects only because it is easier to draw inbetweens in this frame rate. Cut 12 in half and you get 6, cut that in half and you get 3, which means one drawing on the left, one on the right, and right between the two you draw a new inbetween drawing.

When it comes to camera moves (keyframed moves) you must always play in single frames, otherwise your move will look like running next to a picket fence. Therefore for a film for which you draw at 12 fps, you must configure your camera move projects to 24 fps. There is much more to be learned on this subject so don't try to understand everything all at once; it'll come to you in due time.

[slowtiger]

It all depends on which distribution you want. Film is always 24 fps, video is 30 fps or 25 fps, depending on your location. You could even do something just fo the computer screen, 15 fps or 30 fps.

If you work professionally, you need to get used to the idea of a high quality master format from which all others will be derived. Conversion from 24 to 25 fps is easy, as well as the other way round: the difference of 4% in speed isn't noticeable either in motion or sound. Conversion from 24 or 25 to 30 fps is a standard job for any decent post production facility.

Don't mix up frame rate with number of drawings per second. The frame rate is always consistant during an entire film. The number of drawings can change according to what movement you animate. (I've written this quite often before, but can't copy it from the Mirage forum anymore - damn buggers.)

[lemec]

I used to work on Earth Final Conflict, a low-budget scifi TV series. The footage came in at 29.97fps NTSC, but once you took out the pulldown (interlacing), it was just 24fps, progressive-scan. When we were done comping our laser blasts and effects, we put the pulldown back in and the footage became 29.97fps once more.

Most consumer NTSC camcorders in North America do the same thing - they shoot at 29.97fps, but interlace two out of 5 frames, so you're really getting 4 images out of every 5.

30 * 4 / 5 = 24

So even consumer camcorders shoot at 24. In terms of the technology, it's just easier to stick with 24fps and animate on threes, twos or ones, depending on how violent the motion is, or how rapidly things change direction. You'll always need frames for whenever something stops momentarily (like at the apogee of a windup or at the end of a follow-through), and any additional inbetweens should be made for the purpose of "steering" something through a path so that people know how something gets from point A to B. You insert keyframes as necessary to stay in sync with the sound.

[Anim8tor Cathy]

Thanks lemec. I really enjoy your tutorials on YouTube also (I'm a subscriber!)

[Anim8tor Cathy]

There is much more to be learned on this subject so don't try to understand everything all at once; it'll come to you in due time.

Truer words were never spoken. I think I was confusing drawings per second with frames per second. But I seem to be grasping the concept better as I actually do it and see the results.

[lemec]

Truer words were never spoken. I think I was confusing drawings per second with frames per second. But I seem to be grasping the concept better as I actually do it and see the results.

Right -- the frames per second is always a constant number, and often depends on what your target medium is. If it's for film/cinema, it is almost always 24 FPS. For television, however, things get a bit dicey. In North America, the NTSC standard is 29.97 fps, but many shows (and pretty much every movie that is played on television) is shot at 24 and then two out of five frames are interlaced to make it conform to 29.97.

So for optimal frames per second, 24 is a very good and safe bet to go with.

As for drawings per second, this can vary and if you plan on being economical, it WILL vary!. To make things even more complex you might have a stationary element on a layer, like furniture, which doesn't change at all. The drawings-per-second of this layer is well, 0, or less than 1 because it doesn't change. It's static. Other slightly faster moving elements, like rising steam from a coffee mug might be done on a separate layer on twos or even threes, meaning that the drawing changes every other, or every third frame, and so the drawings-per-second becomes 12 for something done on twos, or 8 if it's done on threes.

But if someone slams a door in the room and the draught hits the mugsteam, then for a brief moment, you might want to accelerate that layer up to ones, and include additional drawings to burst the smoke away from the draught, then go back to the lazy twos and threes when the draught settles down.

So frames per second is something that pertains to the overall movie, while drawing per second is something that pertains to specific elements, and will vary depending on how quickly something is moving across the screen, or how quickly it changes direction.