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-   -   Rolling Shutter (http://www.dvinfo.net/forum/sony-hvr-z7-hvr-s270/116807-rolling-shutter.html)

Robert Bec March 11th, 2008 09:20 PM

Rolling Shutter
 
What is a rolling shutter problem i shoot weddings is this going to effect me i heard the picture will warp from the photographers flash.
Has anyone experienced any problems with the Z7

regards

Robert

Chris Soucy March 11th, 2008 10:20 PM

Hi Robert....
 
Go to Google, and type in:

"cmos rolling shutter".

If that doesn't answer your question, I don't know what will.

BTW. A good many of the links lead straight back to DVinfo.


CS

Laurence Kingston March 12th, 2008 09:27 AM

No your picture won't "warp" from a photographer's flash. What you'll see with flashes is that they won't always illuminate the whole frame. This effect will happen top to bottom. In other words, you might see the flash just on the top of the frame or just on the bottom. Whether or not this will bother you or not is something I can't tell you. To me it doesn't look that different from the shadows you get from a flash anyway. It may drive you nuts, but I doubt your customers would even notice.

The "warping' effect comes during very fast pans or jerky hand-held movement. To my eyes, this problem only happens during motion that is too extreme to use anyway.

As far as I'm concerned, the concern with CMOS's rolling shutter is quite overblown.

Andy Wilkinson March 12th, 2008 10:53 AM

Disguising the CMOS Rolling Shutter (Flash) Effect
 
Quote:

Originally Posted by Laurence Kingston (Post 841196)
As far as I'm concerned, the concern with CMOS's rolling shutter is quite overblown.

Yep, I agree!

However, someone posted a good solution on here a while back as well (sorry to that person - but I can't easily find the specific post right now.) Basically, if I remember correctly, what he did was select the instant that the flash appears in the NLE (and as Laurence states, only part of the frame will be flashed/overexposed) and then he overlayed a blank white frame for that brief instant.

I can't remember if he did it as a solid or partly transparent frame - but the result was stated as being a more "natural looking" flash effect. Personally, it does n't bother me so I've not experimented with this idea - but just mentioning it for anyone who needs a potential solution!

Hope this helps!! And if anyone knows the specific post please add the link in here. Thanks!

Andrew Kimery March 12th, 2008 12:28 PM

http://www.spike.com/group/filmfest?...wOption=images

Go to about 30 seconds in and there is a quick snippet of an interview on the red carpet. So many flashes are going off that at one point they look like they are rippling up and down the frame. Some parts of the interview weren't so bad, others were worse. This was shot w/a V1U.

If a big part of your job is shooting events w/flash photography I'd stay away from cameras w/CMOS chips and rolling shutters as long as possible.


-A

Laurence Kingston March 12th, 2008 03:41 PM

The Demi Moore interview is the only place where it is really noticable.

It seems to me like there might be some shutter speeds where the effect is worse than others. Has anybody experimented with this? It might be a simple matter of locking the shutter-speed at slower rate when you know you are going to be fighting with flashes.

Laurence Kingston March 12th, 2008 03:48 PM

There is a really good article about rolling shutter here:

http://dvxuser.com/jason/CMOS-CCD/

Robert Martens March 12th, 2008 04:13 PM

Not a Z7 owner myself, but I thought a link to a post on the Syntheyes forums might be appropriate here: http://www.ssontech.com/phpBB2/viewtopic.php?t=478

Scroll down to the eighth post for sample footage taken from a helicopter to see the worst of it, and go through the rest of the thread for details. Seems rolling shutters (whether modern CMOS sensors or the old tube cameras) cause problems when doing effects work involving a matchmove.

George Sickler March 12th, 2008 07:09 PM

Rolling UGH
 
I have been new to the Rolling Shutter. and find that it is very annoying,
THE BIGGEST issue I find is when we use slow motion. You CANNOT use these clips as the half frame of flash is terrible.

It looks ok when you roll through in real time.

Robert Bec March 12th, 2008 08:12 PM

I think for this time i would rather buy a Z1 or go JVC and then wait until they introduce global shutters to the cmos cameras

Thumbs down Sony

Laurence Kingston March 12th, 2008 09:03 PM

For somebody like myself doing documentaries, it is pretty much a non issue. I see a bit of rolling shutter once in a blue moon. On the other hand, I can see where it would be a real issue for somebody shooting weddings or paparazzi style stuff.

I like the idea of overlaying a single white frame over camera flashes. I use Sony Vegas and I'll bet the whole thing could be automated with a little script.

Chad Dyle March 23rd, 2008 07:48 AM

I have only shot a couple of weddings with my Z7's so far, but I did notice the rolling shutter last night. This totally sucks for anyone that shoots anything with flashes (obviously). Does this problem rear its head under any other conditions?

http://www.chaddyleproductions.com/2...lling_Test.wmv

Bob Ridge March 23rd, 2008 07:51 PM

This wedding highlights clip shot with the Z7U is filled with examples of the rolling shutter in slo-mo. Doesn't concern me one bit, as I don't think my clients care how a flash manifests itself in video - it still looks like a flash.

http://www.indyvisual.com/blog.htm ("Joanna & Louis")

K.C. Luke March 24th, 2008 05:13 AM

Quote:

Originally Posted by Chad Dyle (Post 847036)
I have only shot a couple of weddings with my Z7's so far, but I did notice the rolling shutter last night. This totally sucks for anyone that shoots anything with flashes (obviously). Does this problem rear its head under any other conditions?

http://www.chaddyleproductions.com/2...lling_Test.wmv

When I see this wmv clip is like watching old film stock adding effects. some parts the rolling just roll from top to bottom. is that so bad on this Z7 rolling shutter !!!!!!!!!

Jack Zhang March 24th, 2008 07:13 AM

It's the same ClearVid sensor so if you move it too much, It could be just as bad. That's why the Z1U is still a commodity to matchmovers.


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