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-   Canon VIXIA Series AVCHD and HDV Camcorders (https://www.dvinfo.net/forum/canon-vixia-series-avchd-hdv-camcorders/)
-   -   Is there a method to get rid of the rolling shutter in post? (https://www.dvinfo.net/forum/canon-vixia-series-avchd-hdv-camcorders/110893-there-method-get-rid-rolling-shutter-post.html)

Wes Vasher December 29th, 2007 12:12 PM

What I'm saying is if you depend on capturing light flashes then you probably need to look in a different direction than CMOS, that is all.

The light flashes also don't bother me.

Seun Osewa December 29th, 2007 12:26 PM

In other words, the answer to that question is really "no".

Ian G. Thompson December 29th, 2007 01:24 PM

Quote:

Originally Posted by Wes Vasher (Post 799661)
What I'm saying is if you depend on capturing light flashes then you probably need to look in a different direction than CMOS, that is all.

The light flashes also don't bother me.

Sorry that's my misunderstanding Wes... But you are right. One should get the right camera for the right job.

John Tissavary January 1st, 2008 04:20 AM

The simplest, but necessarily cheapes, fix is to use sync'd strobes or flashes. Other post-fixes have been mentioned, I've got nothing to add there.

cheers,

jt

James Bresnahan January 1st, 2008 08:37 AM

Also, bear in mind that HV20's on-board flash doesn't segment when using the camera in photo mode (dunno why, maybe no rolling shutter when shooting stills.).

Dave Blackhurst January 1st, 2008 06:02 PM

The best way of understanding flash/roling shutter is to realize that the shutter scan is effectively "always" moving -from the top to the bottom at very high speed...

Where the problem happens is if the "action" is moving "faster" than the frame can effectively scan, you'll get a portion of the frame either skewed somewhat, or in the case of a flash, it may occur during part of the cycle on one frame, and the next frame catches the remainder. IOW, you MIGHT catch the flash on a single frame (like the cam itself syncs itself to do), or it may be divided between two frames - it's a timing issue.

In time, no doubt the refresh speed of CMOS sensors will improve enough to eliminate this "feature", but for the moment it's a tradeoff for the other improvements CMOS brings to the table.

Glenn Thomas January 1st, 2008 08:14 PM

I remember there was a script for VirtualDub that was supposed to fix the rolling shutter problem. I tried it once but it made an even bigger mess of things. Guess it depends on the footage.

I knew the HV20 had the rolling shutter when I bought it, but the for low price and image quality it was worth getting anyway. The Red on the other hand, personally I wouldn't pay that much for a camera with rolling shutter artifacts like that. It must be a nightmare for match movers receiving footage from a Red camera? Apparently the Silicon Imaging cameras have it too, but they've improved it by about 50%.

Still, I can't see what's wrong with CCD's. My Ricoh GRD still camera uses a CCD, and the image quality is brilliant. If only they could adapt a CCD like that to work in a video camera.

Mikko Lopponen January 4th, 2008 01:02 AM

Quote:

Originally Posted by James Bresnahan (Post 800758)
Also, bear in mind that HV20's on-board flash doesn't segment when using the camera in photo mode (dunno why, maybe no rolling shutter when shooting stills.).

Same thing when using the HC1 in photomode. No rolling shutter when in photo mode. Not a bit.

Why is that? Why do these cameras exhibit rolling shutter in videomode but not in photomode??

Bernard Racelis January 5th, 2008 03:14 AM

Quote:

Originally Posted by Mikko Lopponen (Post 802353)
Why is that? Why do these cameras exhibit rolling shutter in videomode but not in photomode??

I would think that
(1) The flash on the camera is fired in sync and perfectly timed with the "shutter"
AND
(2) The duration of the flash is long enough for the camera to draw the entire frame.

But when you're recording a video, and a flash fires from another camera, one or both of the above is/are no longer true.


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