Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@y..., Todd Flashner <tflash@e...> 
(snip)
> 
> When I was looking at your print of this image last evening I 
wondered if
> it's possible that whatever occurrence you experience with the sky 
area of
> this image might not be attributable to noise, rather than a busted
> histogram. I assume when you fatigue the the shy it's is through 
darkening
> it, and/or adding contrast. This always seems to expose defects in 
film and
> scans for me. If you were to apply an equal move in the opposite 
direction
> instead, i.e., lightening it how would it look? Heck, lets really 
test it.
> If you put an equal move of lightening/flattening the area AFTER 
your
> darkening/contrast move how does it look? Such a yo-yo move should 
really
> kill the histogram - how much worse for wear does the sky look 
after the
> fore and aft, compared to no move at all?

You actually have a print of a picture I took immediately before the 
one the histograms are from but a very similar situation, although I 
believe the scan of the print you have was PhotoCD and easier to work 
with.

There is a limit of how much adjustment (contrast, brightness, 
levels) you can do before the image degrades. This seems to depend on 
bit depth, the quality of the initial scan (which may be limited by 
the quality of the neg) and the nature of the image. Given the same 
scan quality, you are able to tweak a textured image farther than one 
with large smooth gradients. Not because you aren't getting the same 
amount of posterizing, it's just is harder to see in the texture. 
Also, as Paul pointed out earlier, you also may not see this on 
screen but only when it is printed out. But in most cases, the point 
in 8-bit gray scale where objectionable print quality occurs is way 
past the point where the histogram "dies."

> 
> Isn't testing fun??????

No.

Martin