Noise in dark greens and blacks at DVinfo.net

Go Back   DV Info Net > Sony XAVC / XDCAM / NXCAM / AVCHD / HDV / DV Camera Systems > Sony XDCAM EX Pro Handhelds

Sony XDCAM EX Pro Handhelds
Sony PMW-300, PXW-X200, PXW-X180 (back to EX3 & EX1) recording to SxS flash memory.


Reply
 
Thread Tools Search this Thread
Old January 7th, 2009, 07:17 PM   #1
Major Player
 
Join Date: Mar 2005
Location: Newcastle, Australia
Posts: 337
Noise in dark greens and blacks

Guys,

I am having real trouble getting my EX1 to produce clean blacks and dark greens, They are almost always full of really objectionable noise, though the rest of the picture looks great. Even if I shoot in quite reasonable light the problem presists. At first I thought that I had just set up a picture profile that caused too much noise from one channel, but I have now been testing my camera with no picture profile (yes I know that it is Standard 3), with Doug Jensens "Doug 1" and a few others - always with the same result. A parallel test with a Canon HV20 in the same conditions produces rock solid colours. Is it possible that there is an issue with my cameras gain section, or is there some setting that I have inadvertantly switched that might cause this problem?

Any help here is much appreciated as it is driving me bananas.
__________________
Graeme
Graeme Fullick is offline   Reply With Quote
Old January 7th, 2009, 07:43 PM   #2
Inner Circle
 
Join Date: Nov 2006
Location: Tallahassee, FL
Posts: 4,100
Two questions:

1. What is: "...quite reasonable light"? How much light are you talking?

2. What is your gain set to?

Is it possible for you to post a still image of what you're seeing as well as your camera settings (iris, gain, light level in lux/FC)?
__________________
DVX100, PMW-EX1, Canon 550D, FigRig, Dell Octocore, Avid MC4/5, MB Looks, RedCineX, Matrox MX02 mini, GTech RAID, Edirol R-4, Senn. G2 Evo, Countryman, Moles and Lowels.
Perrone Ford is offline   Reply With Quote
Old January 7th, 2009, 07:59 PM   #3
Major Player
 
Join Date: Mar 2005
Location: Newcastle, Australia
Posts: 337
Perrone,

THanks for the quick reply.

Reasonable light is a typical dull overcast day at midday - can't tell you what lux that is, but auto iris was giving me about F4 with no ND filters, and centre light meter was about 38% on the dark green jacket that I was testing. Gain was set at -3dB.

The Canon HV20 on the same scene produced a rock solid green with no noise.

I have subsequently done an iris closed test at both 0dB and -3db - both have subtle green noise spots in the picture. My repair agent tells me that at 0dB there should be no noise for an iris closed test - so I now suspect a problem with either the CMOS block or the processor board. Either way it looks like a trip to the repair agent.
__________________
Graeme
Graeme Fullick is offline   Reply With Quote
Old January 7th, 2009, 08:37 PM   #4
Inner Circle
 
Join Date: Nov 2006
Location: Tallahassee, FL
Posts: 4,100
By chance, have you done a black balance on the camera to tell it what "black" actually should be?
__________________
DVX100, PMW-EX1, Canon 550D, FigRig, Dell Octocore, Avid MC4/5, MB Looks, RedCineX, Matrox MX02 mini, GTech RAID, Edirol R-4, Senn. G2 Evo, Countryman, Moles and Lowels.
Perrone Ford is offline   Reply With Quote
Old January 7th, 2009, 09:44 PM   #5
Major Player
 
Join Date: May 2006
Location: australia
Posts: 407
Quote:
Originally Posted by Perrone Ford View Post
By chance, have you done a black balance on the camera to tell it what "black" actually should be?
So, a Black Balance, what was the best way to get a good result ?
__________________
Rob.
www.rpbproductions.com
robert@rpbproductions.com

HD101/G5 Mac/4gig Ram/1TB HDD/30" Cinema Display/FCP.
Robert Bale is offline   Reply With Quote
Old January 7th, 2009, 10:07 PM   #6
Inner Circle
 
Join Date: Nov 2006
Location: Tallahassee, FL
Posts: 4,100
Not sure I understand your question.
__________________
DVX100, PMW-EX1, Canon 550D, FigRig, Dell Octocore, Avid MC4/5, MB Looks, RedCineX, Matrox MX02 mini, GTech RAID, Edirol R-4, Senn. G2 Evo, Countryman, Moles and Lowels.
Perrone Ford is offline   Reply With Quote
Old January 7th, 2009, 10:20 PM   #7
Major Player
 
Join Date: May 2006
Location: australia
Posts: 407
Quote:
Originally Posted by Perrone Ford View Post
Not sure I understand your question.
Sorry, what it the best way to set it, do i do like i would manual white balance?
__________________
Rob.
www.rpbproductions.com
robert@rpbproductions.com

HD101/G5 Mac/4gig Ram/1TB HDD/30" Cinema Display/FCP.
Robert Bale is offline   Reply With Quote
Old January 7th, 2009, 10:31 PM   #8
Inner Circle
 
Join Date: Nov 2006
Location: Tallahassee, FL
Posts: 4,100
Yea, close the lens cover and the iris. On the EX1 it's apparently in the maintainance menu. I've not done it, and I need to.
__________________
DVX100, PMW-EX1, Canon 550D, FigRig, Dell Octocore, Avid MC4/5, MB Looks, RedCineX, Matrox MX02 mini, GTech RAID, Edirol R-4, Senn. G2 Evo, Countryman, Moles and Lowels.
Perrone Ford is offline   Reply With Quote
Old January 7th, 2009, 10:50 PM   #9
Major Player
 
Join Date: Mar 2005
Location: Newcastle, Australia
Posts: 337
Perrone,

The authorised Sony repair agent thinks that what I have is far more significant than a black balance. As it is only the greens and blacks (which look brownish from noise) that seem affected. When I do a close lens 0 gain test I see green noise flecks in the picture that should be black.
__________________
Graeme
Graeme Fullick is offline   Reply With Quote
Old January 7th, 2009, 11:02 PM   #10
Inner Circle
 
Join Date: Nov 2006
Location: Tallahassee, FL
Posts: 4,100
Well, let them have a look by all means, and report back what they find. This one is curious...
__________________
DVX100, PMW-EX1, Canon 550D, FigRig, Dell Octocore, Avid MC4/5, MB Looks, RedCineX, Matrox MX02 mini, GTech RAID, Edirol R-4, Senn. G2 Evo, Countryman, Moles and Lowels.
Perrone Ford is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > Sony XAVC / XDCAM / NXCAM / AVCHD / HDV / DV Camera Systems > Sony XDCAM EX Pro Handhelds

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 01:16 PM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network