There seems to be a fair amount of noise in the pix generated by my DS.
Here are two examples - each 100% crops - taken directly from unmanipulated
PEF files. I've noticed this since the very first pix I took.
http://home.earthlink.net/~scbelinkoff/bmw_noise.jpg
http://home.earthlink.net/~scbelinkoff/pic_noise.jpg
The first was shot @ 200 ISO, where the DS is supposed to be virtually
noiseless, the second @ 400 ISO.
What could be causing this noise? Underexposure? Some camera setting that
needs changing or adjustment? I can clean it up a bit with ACR, but should
that be necessary?
I would speculate that it's underexposed. I would say to look at
the histogram, but both the in-camera and most RAW converters' histogram
are done after the gamma-correction, brightness, and contrast settings
have already been applied. I use 'ufraw' for one of my RAW converters and
it will show the before and after histogram.
My experience has been that the -DS tends to underexpose by about
to 1 stop in typical compositions if left to its own decision. That's
good to prevent blown highlights, but bad for shadow and mid-tone noise.
If your RAW converter and workflow allow, try making a RAW conversion to
16-bit linear TIFF (without *any* adjustments or color profiles applied).
Look at the histogram on the resulting deep color image to find out what
exposure the sensor *REALLY* saw.
-Cory
--
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* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
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