Using High Shutter Speeds With 60i-24p?

[Luke McMillian]

Hey all,

I've been doing some excellent video experimenting with DV filmmaker using 60i footage converted to 24p shot with a 1/60th shutter speed. For my next video, I want to use a high shutter speed for some action scenes and my question is what exactly happens to footage shot with a high shutter speed when converted to 24p. Will it look just utterly horrible, or at least watchable?

Would my better bet be to shoot scenes with high shutter speed and include them in the video timeline, do not interlace them, and deinterlace the rest of the 1/60th shutter speed footage as usual?

My workflow is 60i footage into pc, deinterlace with dv filmmaker to 24p, then import 24p footage into adobe premiere elements, and burn from there, I get great results, but high shutter speed video plauges me now..

Please help

Luke

What does everybody else do?

[Marcus Marchesseault]

I'm confused. The shutter speed has no effect on the frame rate. You should not need to change your workflow in any way. High shutter speed footage simply lacks motion blur, but it is otherwise identical to other footage shot at 60i.

What problem are you having? Are you getting some sort of motion or compression artifacts?

[Dylan Pank]

At 24p, high shutter speed (100/sec or higher) will give you something like the Omaha Beach scenes in Saving Private Ryan (the other differences between video and 35mm aside).

What camera/format are you using?One side effect in HDV for example might be that MPEG compression artefacts may be more severe because in high motion sequences, the motion blur of 50/sec means the compressor has an easier time with the fast changing image. That's not the case in higher shutter speeds with less motion blur. In DV or DVCproHD this would not be an issue.

[Ben Winter]

Originally Posted by Marcus Marchesseault

I'm confused. The shutter speed has no effect on the frame rate. You should not need to change your workflow in any way. High shutter speed footage simply lacks motion blur, but it is otherwise identical to other footage shot at 60i.

What problem are you having? Are you getting some sort of motion or compression artifacts?

It's a legitimate concern. DVFIlm suggests specifically that the shooter use a 1/60 shutter for best 24p conversion results, but that's just to make it closest to film.

Luke, you're in luck. I use an FX1 and DVFilm Maker and you can view an entire scene of my movie www.thelifeguardmovie.com that was shot at a high shutter speed because (1) we wanted slow-motion capability later and (2) it was a high action scene and wanted that stuttery look. 24p conversion works fine with it. If you watch this movie, watch the last scene at the pool before the credits, it was shot completely at 1/250 and above. Yes, we did experience HDV compression artifacts unfortuantely, which is really unavoidable with all the movement we were doing but for the most part we edited out those wacky frames (1 or two in the whole bunch, no biggie).

[Luke McMillian]

Thank you so much Ben, you answered my questions perfect! All the best with your film!

Luke

[Marcus van Bavel]

Originally Posted by Marcus Marchesseault

I'm confused. The shutter speed has no effect on the frame rate. You should not need to change your workflow in any way. High shutter speed footage simply lacks motion blur, but it is otherwise identical to other footage shot at 60i.

What problem are you having? Are you getting some sort of motion or compression artifacts?

DVFilm Maker blends fields to convert to 24p. If you shoot 1/60th sec the motion blur in the camera is such that the blur endpoint of one field touches the blur begin point of the next field, so if the fields are blended together the blurs "join" seamlessly, so to speak.

If a higher shutter speed than 1/60th is used then the blended fields do not join and you get a double-image effect on some frames, which is usually (but not always) undesireable. One way around it for a non-sync shot is to convert the 60i to 30P instead and slow it down 20% to 24P.