Canon 7D problem even with slow PAN’s (so it’s not rolling shutter?)

[Todd Terry]

If anyone has ever watched an feature film on one of these new displays that “help” the viewer by interpolating “missing” frames you’ll quickly see the problem… it looks like crap. Buy one if you want to see a $50 million dollar feature film look like a home movie. It’s horrible.

“can produce a somewhat video-esque quality to the whole, the improvement to motion heavy sequences is undeniable”

Depends on what you think “improvement” is, I guess. Making footage look more like video and making action sequences look like instant TV news footage wouldn’t be considered an improvement by most filmmakers.

I finally got around to looking at the footage in question from the first post. That is not a rolling shutter issue. That is a frames issue. I’m assuming from your specs that the footage is 25fps and you are actually using it on a 25fps timeline as well. If there is an inconsistency in those two, you will have that kind of problem. The second shot is likely exhibiting problems because you said it was “speeded up a little bit in FCP.” That can be a big problem. Unless you are changing the speed by an exact multiple of the main timeline (such as doubling it, or halving it) you can run into problems because it can no longer be displayed frame-for-frame. By increasing its speed “a little” (we don’t know by what amount), your NLE is having to drop frames here and there to account for the time difference… thus giving you the jerky movement. I don’t know about FCP, but in Premiere you can turn on the “Frame Blending” feature for shots that are not at 100% speed which helps some.

As to one comment that was deleted… no, shutter speeds and frame rates are not constant. A “normal” shutter speed is considered that speed which would be equivalent to a 180° shutter in a film camera. I.e., if your frame rate is 24fps, a “normal” shutter would be 1/48th of a second. If your frame rate is 30fps, a “normal” shutter would be 1/60th. But they don’t have to be… they can be faster or slower than “normal” with the decision made for aesthetic (or for exposure) reasons. Often action sequences (the most frequent example) are shot with higher shutter speeds to freeze the action in each frame and make the scene look…well… more “actiony.” See Saving Private Ryan to see this done well. See Gladiator to see this done waaaaaay over the top.

T2

__________________________________
Todd Terry
Creative Director
Fantastic Plastic Entertainment, Inc.
fantasticplastic.com

[Al Bergstein]

Thanks Terry, I removed my post on that for that very reason. Easy to post without giving it enough thought. I so rarely think about changing the shutter when I shift to a faster FPS.

I didn’t catch his discussion about speeding it up a bit in FCP, I thought that was what he did to ‘fix’ the problem that already was there.

Anyway, thanks for that post, it’s a good learning point to remember for those of us that haven’t used a fully manual movie camera in decades!

Alf

[Osku Petteri]

Hello and many thanks for the answers,

I’ve been on a vacation and just got back.

QUOTE:
That is not a rolling shutter issue. That is a frames issue. I’m assuming from your specs that the footage is 25fps and you are actually using it on a 25fps timeline as well. If there is an inconsistency in those two, you will have that kind of problem. The second shot is likely exhibiting problems because you said it was “speeded up a little bit in FCP.” That can be a big problem. Unless you are changing the speed by an exact multiple of the main timeline (such as doubling it, or halving it) you can run into problems because it can no longer be displayed frame-for-frame. By increasing its speed “a little” (we don’t know by what amount), your NLE is having to drop frames here and there to account for the time difference… thus giving you the jerky movement. I don’t know about FCP, but in Premiere you can turn on the “Frame Blending” feature for shots that are not at 100% speed which helps some.

I am quite sure the issue was there before. It could be seen when watching the raw material. Yes Final Cut also has frame blending but it is usually really crap since it looks like it’s just blurring half of the frames in between.

Correct it was 25fps on a 25fps timeline.

Actually what i’m gonna do is go back to the material and check it without the speed changes. I’ll get back to you cause that seems quite reasonable solution.

Thanks guys,

-Osku-

[Osku Petteri]

Are you sure about this? 7D Manual says that for VIDEO your card should do at least 8MB/sec read and write.

-Osku