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Canon C300 issue - horizontal rolling shutter?

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Matt Walker
Canon C300 issue - horizontal rolling shutter?
on Dec 16, 2012 at 11:12:11 am

Hello all,

I've just started a new job as videographer and I've gone from using a Canon 550D/ Sony Cybershot for my movie making to a Canon C300 and there are a few issues I'm having, mostly the formalising of my self-taught knowledge into real-world theory/ terminology and understanding etc but the most significant issue I'm having is the following:

I shoot at 1080p, 24p, 50mbps transfer rate and shutter speed of 50fps.

The trouble is that when I pan (in either direction) through the horizontal axis, there is often a 'jitter' where there appears to be a frame dropped or something. It does appear to improve if I move pretty damn slow but that defeats my objective a lot.

I'm writing to class 10 CF cards and using Premiere Pro CS6 - all updated etc.

Are there any suggestions on this? Im getting quite frustrated as I've only had Rolling Shutter before and feel a bit intimidated by the camera presently. I've been in post 1.5months now and have made significant headway but this and a consistent exposure are the problems I'm having.


I shoot in CLog for the wider latitude for editing but my exposures seem wildly mismatched even though i set a custom white balance with pure white paper under the lighting conditions I'm filming in.


Any help whatsoever is massively appreciated.


Big thanks,


Matt

I came, I saw, I shall take copious notes.


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Todd Terry
Re: Canon C300 issue - horizontal rolling shutter?
on Dec 16, 2012 at 6:03:56 pm

I shoot with the C300PL every day. LOVE this camera, it's one of my all-time favs. I haven't seen your problem exactly... the C300 will give you a rolling shutter on fast pans, although it is not nearly as severe as, say, a DSLR. But it looks like just the usual rolling shutter effect... vertical lines "slanting" just a little bit during the pan. The effect you are describing does not sound like a rolling shutter issue at all, it sounds like something else..

So, I don't have any answer or solution, but do have a few questions/observations that might help figure it out....


[Matt Walker] "I shoot at 1080p, 24p, 50mbps transfer... "

Are you sure you are shooting at true 24p? Or are you actually shooting at 23.976p? The camera will do both, obviously, but if you are shooting at 24 and are using that footage on a 23.976 timeline in Premiere CS6 you might occasionally see some issues (although usually Premiere will ask you if you try to use a clip with a different frame rate on a timeline). Customarily most people choose to both shoot and edit at 23.976 unless you are planning to strike a real celluloid film print from the finished project.

Secondly, are you sure this artifact is happening to the raw footage? Or are you just seeing it in Premiere? If you replay a shot in camera right after you shoot it, do you see this effect on the camera's screen or on an external monitor connected to the camera?

When you have a shot on your timeline, slowly step through one of the "bad" areas frame by frame. You said it looks like frames are being dropped... but that will let you know if they actually are being dropped, or if something else is going on.


[Matt Walker] "...and shutter speed of 50fps."

Ok, that puzzles me a little bit. Firstly, and just a semantic technicality, shutter speeds aren't expressed in terms of fps. A shutter speed of "50" is 1/50th of a second, not 50fps. But that's neither here nor there. What's strange about that is I don't think the C300 when shooting 24p will let you set the shutter speed to 50 (I'm not completely sure because I don't have the camera in front of me). But I think the nearest available shutter speed would be 1/48th (I could be wrong, but I don't think so). That makes me think something else weird is going on though, or there is a wrong setting somewhere.


[Matt Walker] "exposures seem wildly mismatched even though i set a custom white balance"

Are you shooting with Canon EF lenses or cine PL-mount lenses? How are you setting exposures?...by eyeballing it with the viewfinder or an external monitor? If so I'd suggest switching on the waveform monitor (the WFM button on the control panel). That will give you a much better idea of what your exposures actually are. Especially when shooting in the C-log mode the viewfinders are not always true representatives of exposure levels (in other modes the viewfinders are fine, but in C-log not so much, even when you turn on the level-boosting feature of the finders). Gotta use the waveform. When or how you set your white balance is irrelevant... white balance has nothing to do with exposure at all, those are two completely different and separate things. For what it's worth I never ever actually "white balance" (I'd even have to take a minute to figure out how to do it that way). Instead I use the side wheel to dial in the exact degree of color temp I want. It's a lot easier and faster than setting a real white balance, you don't need a white card or object, and you are able to really finesse it and dial in a color temperature that looks like you want for a particular scene.

Let us know how it's going and if any of these observations lead you to a solution.

T2

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



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Matt Walker
Re: Canon C300 issue - horizontal rolling shutter?
on Dec 17, 2012 at 8:00:48 am

Hi Todd,

Thanks for the speedy reply. Firstly, noob faux-pas - it was 1/50th sec not 50fps. I shall check out your suggestions and see what the deal is and if it seems native to PP.

Will be in touch - thanks again!

Matt

I came, I saw, I shall take copious notes.


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