more FPS..???

[Chris Fritsche]

Is it good to shoot at more FPS, I mean in some of the things I want to do, I would like to have very crisp slow motion, wouldn't you need more FPS to accomplish this?

[Nick Vaughan]

How slow? I mean, 60i is gonna give you the best overall outcome if you're slowing it down, but it's no good if you're talking, like, Matrix-esque.

[Tom Hardwick]

You can't vary the fps rate, period. Super-8 film cameras can shoot at 80 fps for beautifully fluid slo-mo, but video cameras (at least the ones we're talking about here) have to shoot 60 half resolution fields for NTSC or 50 for PAL. All you can hope for is that post production slo-mo will interpolate between fields (the best ones do) but this 'guessing' at info is a long way from 80 real images per second, projected at 24 fps.

So for the best slo mo, shoot at 1/60th sec (NTSC) and slow in post. Remember that as soon as you slow-mo in the slightest you lose resolution, and if you go to half speed (a pretty feeble slo-mo really) you're immediately down to half vertical resolution. This is quite a cross to bear.

tom.

[Ash Greyson]

There are many programs/plug-ins that can do great slo-mo, they are expensive and have quite a learning curve. I have seen great DV slo-mo come out of both After Effects and Shake...


ash =o)

[Patrick Pai]

I've used Twixtor along with the Fields Kit Deinterlacer for both slow motion and conversion from 60 Fps interlaced video to 24fps progressive. (I sometimes get footage from sources other than my XL2). These tools are excellent, but require a significant learning curve. Twixtor and FKD both use sophisticated motion estimation techniques to interpolate the extra fields/frames you need.

You can download demo versions of these tools which will paint a watermark on your video until you purchase a license. You may find that FKD is not necessary as Twixtor includes a lower-performance deinterlacing algorithm. These tools do seem expensive, but I've found the results well worth the purchase cost involved.

One suggestion I would make is when capturing video you know you will want slow-mo, capture at 60i with a high shutter speed. This will increase the quality of the generated frames, and any motion blur can be added later with Twixtor.

For Twixtor, see:
http://www.revisionfx.com/rstwixtor.htm

And for FKD see:
http://www.revisionfx.com/rsfk.htm

Pat

[Tom Hardwick]

Just to correct a general misapprehension Pat, but upping the shutter speed doesn't ''increase the quality of the generated frames''. Of course it'll help to remove motion blur (camera or subject generated), and there are times when it'll increase resolution, but they're small aperture, diffraction specific situations.

pedantic tom.

[Patrick Pai]

Correct, Tom. I wrote without thinking carefully on the reasoning. I still stand by a higher shutter speed for interpolating (generating) frames, because slow-motion footage is typically shot at a higher shutter speed, necessitated by the higher frame rate. I try to shoot with minimum motion blur in slow-mo (less than will be in the final footage), because while blur may be a desired characteristic in motion pictures, it is a loss of information when pixel information is smeared across several sites due to movement while the shutter is open. The desired level of blurring can always be introduced later. The reasoning that I use here is that while I can very easily introduce the blur in post while interpolating the frames, I can't take it out later if I decide I want less. This allows me the freedom of setting the overall speed reduction later, tuning it to the feel and length of time that I want.

This doesn't mean, of course, that I'll crank up the shutter speed to the maximum I can get. Part of the fun is including this consideration in the typical tradeoffs of shutter/aperture/gain(ISO) when setting up a shot.

Pat