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-   -   bad footage - my hunch about it (https://www.dvinfo.net/forum/open-dv-discussion/497000-bad-footage-my-hunch-about.html)

Philip Fass June 10th, 2011 10:39 AM

bad footage - my hunch about it
 
I did a long sit-down interview in a room where I had plenty of light and the camera's (Canon H1) waveform monitor was nicely spread between black and 100. But when I brought it into FCP, it was extremely grainy. The kind of look I usually expect from underexposure. In fact, the guy's face was slightly overexposed.

The only thing I can think of is that he was wearing a bright red shirt, which filled a good chunk of the frame. I wonder if this color was too much for the camera to handle.

I told him not to wear white or small patterns, but didn't say anything about red.

Fortunately I can get the shots to look decent with the Neat Effects noise filter. Still, I'm kicking myself.

Chris Medico June 10th, 2011 11:30 AM

Re: bad footage - my hunch about it
 
What mode was the camera in? Was it in manual or one of the program modes?

Philip Fass June 10th, 2011 11:34 AM

Re: bad footage - my hunch about it
 
I had it in Av mode and adjusted according to waveform.

Again, if anything it was a little overexposed for the face.

Chris Medico June 10th, 2011 12:08 PM

Re: bad footage - my hunch about it
 
Hm..

Was the GAIN set to AUTO in the menu?

That could have caused the noise to be more pronounced if the GAIN was being bumped up in auto.

Philip Fass June 10th, 2011 01:12 PM

Re: bad footage - my hunch about it
 
The gain was set to Auto, but has been set that way for about 15 different interviews. About 3 have been grainy and needed the noise filter, but I really don't think they lacked enough light. It seems almost random, and I wonder if it's a problem in the camera itself. (I know, a poor craftsman blames his tools!)

Garrett Low June 10th, 2011 01:59 PM

Re: bad footage - my hunch about it
 
Philip, to start with you should not have the camera's gain setting to auto. Also, shooting in Av Mode is something you should avoid. Av mode allows you to set the aperture but will vary the shutter speed as needed to compensate for correct exposure. Varying the shutter speed during a take is the last thing you want to do. But, in a setting as you described there shouldn't have been much variation in lighting so the shutter speed may not have changed.

As for the grain you described, without seeing the footage or a screen shot I can't be sure, but you are probably seeing noise introduced from the camera pumping up the gain. One of the things with the Canon XH/XL cameras is that they are not very light sensitive. They also tend to overexpose when in one of the program modes. When I was shooting with them, I would be in full manual 99% of the time. The only time I would run a program mode it would be Tv and gain never set to auto. I also had the AE shift set to about -0.5 or -0.75. Is there a way to see what the gain settings were for your shoot? In most cases I would try to shoot with -3 gain but never over +3.

-Garrett

Chris Medico June 10th, 2011 02:05 PM

Re: bad footage - my hunch about it
 
Phillip, Can you post an image or better yet a short clip of the video in question?

My gut feeling is that AUTO GAIN reared up and bit you. :(

Frans Meijer June 11th, 2011 12:35 AM

Re: bad footage - my hunch about it
 
Could have had ND filters on - or any other setting that reduces light - and the camera compensated with (auto) gain.


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