Food for thought regarding Digital Cinema vs Film

[Jeff Kilgroe]

Also, when special effects are being created in post, they'll spend a lot less time trying to make them blurry like 24fps film.

The blur is often your friend... It can cover lots of nasties. Not to mention that 60fps would require processing and/or rendering of 2.5 X as many frames.

I'm all for 60fps and the extra clarity though... I'm anxious to work with it and see how cinematic it can be made to look. 720p60 from the HVX200 almost always looks like video no matter what you do with it.

 

[Nick Shaw]

http://www.bbc.co.uk/rd/pubs/whp/whp-pdf-files/WHP034.pdf

 

[Thomas Mathai]

I haven't seen mention of frame rate here. I think most significantly, "temporal resolution" will be vastly improved by usage of the 60fps frame rate. Then when you are panning right or left, you'll actually be able to read words and signs, as well as see movement very clearly.

Also, when special effects are being created in post, they'll spend a lot less time trying to make them blurry like 24fps film.

I think the real unspoken potential here will be in camera HDR when you have 90 fps data rates and some sort of digital aperture. (Red two?) You could then have a 30fps clip with three exposure levels for each frame being composited in-camera.

http://en.wikipedia.org/wiki/High_dynamic_range_imaging

They may spend less time trying to make blurry images, but they will spend more time just doing even basic effects work because there's be 2.5 times more frames to work with for the same time duration.

This in turn raises the costs because no fx house wants to do more work for less, though they may be forced to.

 

[kraemer]

Not to mention that 60fps would require processing and/or rendering of 2.5 X as many frames.

spend more time just doing even basic effects work because there's be 2.5 times more frames to work with for the same time duration.

Thats technically not correct. A majority of the time spent is getting an animation to look right at 24Hz and then making it look like the existing piece of film. The lower the frame rate the harder it is to integrate, not easier. A really significant amount of computing power goes into the process of taking the animation through an accumulation buffer to "filmize" it.

Faster frame rates = easier. Ask around.

 

[Nick Shaw]

One of the larger rendering time hits in 3D or compositing is the calculation of motion blur. Just try rendering a simple animation in After Effects as both fields and frames(at eg 25fps). The frames version often takes longer to render, as you can get away with switching motion blur off for a lot of the layers, whereas the frames version needs motion blur on for pretty much any layer that moves.

The relationship between fps and rendering time is certainly not linear, and with careful tweaking of the render settings it is possible to make more fps render in less time.

Nick

 

[Jeff Kilgroe]

Hmmm...

I suppose it depends on the level of animation, detail, complexity, etc.. Considering most of the animation work I do (which is mostly what I do these days), motion blur is a small percentage of the render calcs. It also depends on the render system being used. Many newer GI implementations can get various types of motion blur for free in the calcs simply by offsetting the framing or directional camera vectors between render iterations. -- Actually, that is specifically how many render algorithms generate blur these days and much of the motion blur or adaptive sampling is part of the anti-aliasing or iterative render process. Animations in After Effects or Motion is one thing and I can see where higher speed/fps with less blur can be beneficial. But when we're talking rendering of scenes from Mental Ray, F-Prime, Renderman, etc.. And frame render times are measured in hours, not minutes for 10s of millions of polygons with blur effects as rendered or addes as post process are only a fraction of that render time, it's a whole different ballgame. 24p with more blur to add obscurity can be a much faster workflow than trying to do 30p or 60p. Even at 60p, the renderer must still generate motion blur to match with the blur length of any combined footage. Otherwise it just looks like a video game... Oh wait, newer game engines are incorporating real-time motion blur too. Hmmm.

 

[Nick Shaw]

Jeff, I'll bow to your superior knowledge on the 3D front! I put that in without really thinking about it, and 3D is not relly my area of expertise. It has however definitely been my experience that it is the case with 2D, in both After Effects and Shake. I'm still running After Effects 6.5, so can't comment on how much GPU acceleration in v7 helps, but certainly Shake (no GPU acceleration) takes a big render speed hit for each element you turn on motion blur for.

Nick

 

[Jeff Kilgroe]

Sure Nick.. I agree with you on the 2D ftront. AE, Shake, Fusion, etc.. doing 2D animation work or combining pre-rendered graphical elements where blur must be added manually, is a whole different animal. And yes, that does take more time to add proper motion blur to 24p in that respect. I have to admit, when I originally posted the "rendering 2.5X as many frames" comment that I completely ignored this side of the coin.

 

[Thomas Mathai]

Thats technically not correct. A majority of the time spent is getting an animation to look right at 24Hz and then making it look like the existing piece of film. The lower the frame rate the harder it is to integrate, not easier. A really significant amount of computing power goes into the process of taking the animation through an accumulation buffer to "filmize" it.

Faster frame rates = easier. Ask around.

A good amount of bread and butter fx work is fix work, not animation, so paint and roto will take longer for sure.

A lot of animation is rendered in layers, to be comped together later, so motion blur can be finessed on the 2d side. It would still be 2.5x times more data for the same time duration.

By the way I did ask a 3d artist who does a ton of film work and she has never had an issue with creating animation at 24fps, and have it integrate back into the film plates.

Making an animation look good has more to do with the skills of the animator not the frame rate or software.

Software doesn't care what the frame rate is, so I don't see how more computing power gets used up for a lower frame rate.

Since pretty much a ton of great animation has been done at 24fps, I'm not sure it's such a big deal.

There has been experimental formats like ShowScan that use 60fps and has been used mostly in immersive motion simulator rides.

 

[Jeff Kilgroe]

Yep, Thomas that sums it up.

You'll also find that when creating animation for broadcast, DVD, etc.. where the animation isn't being matched with video elements, many animators (myself included) will usually still work in 24p at times or will go 25p for PAL or 30p NTSC. It's typically faster to render animation data for 30 progressive frames than it is to render for 60 interlaced fields. While the render calcs themselves take up about the same amount of time for one full res progressive frame as they do for two half-res fields, when considering moving elements and 3D geometry, the computer must re-calculate mesh data and vertex positions for each field just as it would for indidvidual frames.

Also like you said, doing fix work or rotoscope operations, the fewer the frames to work with the better. But maybe not, I've been known to charge by the hour on occasion and I kinda like that sometimes.