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.

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)?

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.

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 ?

Not sure I understand your question.

Sorry, what it the best way to set it, do i do like i would manual white balance?

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.

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.

Well, let them have a look by all means, and report back what they find. This one is curious...