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D5 MII frame conversion


Paul Bruening

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Hypothetically speaking, if I put a Canon D5 MII in my scan rig and ran the film head at synced, 30 fps, and captured the images in the D5's 1920X video, could I simply realign the footage in Premiere or AE to run at 24 fps? The idea being, get around the 30/24 difference by simply running the film at 30 fps and slowing it to 24 fps in post. That would allow me to use one camera for both mid-res workprint and high-res, frame scans.

 

Crazy or possible?

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Well, converting the framerate from 30p to 24p is said to be very difficult and can leave the footage choppy or with artifacts.

 

You can, however, very easily choose "Interpret Footage" and set the 30p clip to run at 24p in your 24p timeline, meaning that it will have a very slight slo mo effect.

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Hi, this is my first post, hopefully this may be interesting in the case of 5D Mark2 frame rate conversion.

To 1:1 downconvert 30p to 24p/25p the best is to use a software that uses warping. This retiming software will analyse the motion in the movie clip and then blend the frames using the generated motion vectors. It so creates the inbetween frames that are missing without the double or ghosting images that scare the hell out of every broadcaster/filmmaker. There are a couple of these retiming plug-ins for FCP or AE.

There are 3 minor issues though:

1. long rendering time (1 sec. is one minute render-time on my dualcore laptop when i use 1080 full HD)

2. slight increase of motion blur

3. visible artefacts in areas with fast motion

 

This method works best for me if i need 30p to 25p. For non sync stuff, Tom Lowe's post described it best.

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Hey Oliver,

 

I probably didn't clarify my post well enough. I was asking about rigging my DIY telecine by running the projector at 30 fps. Then, when I capture the images with the 5DMII at 30P it will still be a one-to-one frame capture... a kind of cheating, if you will. Then, I have to only drop the frames into a 24 fps timeline (which I didn't actually know originally and Sam answered). The footage, which was shot in the film camera at 24 fps will now play digitally in the editor at 24 fps and make sense. It's just a cheat to exploit the 5DMII's fine characteristics for a good quality, real time, HD sized capture. The same set-up can then get 5.5K, single frame, sequential scans. Not a bad prospect that only requires that I control my new-junk projector motor at an accurate 30 fps. It's all theoretical anyway. I can't buy a 5DMII. I'm a broke daydreamer.

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I just shot with the mk2 for a german TV documentary. The footage needs to be 25 fps in Final Cut so i used Cinema Tools to conform it to 25p with no recompression. For just the scenes where i have dialogue (that was recorded externally with a sound devices hd recorder BTW) i have to speed up the footage in FCP to 120%. This workaround does it very well for me. If i have the time i will process just the dialogue scenes in After Effects with the built in retiming tools (these use the vector technique i decribed above).

 

Paul, IMHO your telecine method would work pretty well, conforming the frame rate down to 24 works great. Just make sure your projection is steady, has no rollbars or flicker etc. Just from my experience in capturing 8mm or 16mm projections on video. Although i have not tried it with the mk2 i think that the progressive scan should be a real quality improvement doing this. (as is for me in every aspect of production work, having spent days getting rid of the fields in interlaced footage for web etc.)

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Hi, this is my first post, hopefully this may be interesting in the case of 5D Mark2 frame rate conversion.

To 1:1 downconvert 30p to 24p/25p the best is to use a software that uses warping. This retiming software will analyse the motion in the movie clip and then blend the frames using the generated motion vectors. It so creates the inbetween frames that are missing without the double or ghosting images that scare the hell out of every broadcaster/filmmaker. There are a couple of these retiming plug-ins for FCP or AE.

What's the best in your opinion?

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Hi Chris,

which software do you use?

Retimer is the original software i saw things like this happening. It's Standalone PC only..

Twixtor is very complex for this. The Reelsmart Motion Blur works for this and it only is an only 100 $ purchase.

When you use AE CS4 try this: www.okayfilm.com/temp/FRCONVERT.ffx

I don't know if it works with earlier versions of AE and i don't think so.

I found this on a tutorial website but can't remember which (think it was creative cow) so i'm not taking any credit for the plugin here.

Edited by Oliver Christoph Kochs
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I recently got a chance to single frame through some test material at a post facility on high quality monitors. Unfortunately, it was just some dialogue c/u's and hand held stuff of people walking with a few car-by's, but I think I see how they do it. We looked at stuff from both Twixtor and the post facility's secret sauce process.

 

They have to turn five frames into four frames. It appears that they take three frames straight across, and then create an in-between from the next two. The in-between is what takes all the rendering, as they find the motion blur in the two frames, and fill in more blur to make it continuous. The net effect is that you have four frames, one of which has more motion blur that the rest.

 

If we consider the timing of the blur-between frame and the middle frame of the three straight across to be "right", then the other two straight across frames are one a tiny bit early, and the other a tiny bit late. That gives the motion a slight 3-2-ishness. If you shoot with a 180 degree shutter angle, the three straight across frames look as if they were shot with a 144 degree shutter, while the blur-between is equivalent to a 432 degree shutter.

 

It's not too bad on dialogue, where the motion is mostly mouths. If you single frame thru looking for eye blinks, you can see a massive artifact if a blink lands on a blur-between. Eyelids move fast enough that one frame can be just an open eye, so the software can't find the motion vectors of a blur to use.

 

All in all, this is really shaky and marginal and very content dependent. The right answer is to wait for Canon to make a model that really does 24 and 25. Clocking the electronics slower is a no-brainer.

 

 

 

 

-- J.S.

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I'm about to do a bunch of conversion like this from a 5D. I'm not holding my breath for it to be any good. The h.264 compression is harsh enough as it is.

 

See my post elsewhere about how clear it is that the problems with this thing are politically-motivated.

 

P

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