Re: [APML] McBeth Color Card

[Jerry Lodriguss <jml@astropix.com>]

>
>Thanks, I assumed you would have an answer.  The raw negative scan is 
>linearly stretched compared to the raw positive scan (i.e., the slope is 
>-1.25 instead of -1).  I thought a gamma correction would impart a 
>nonlinear curve to the results.  I'm just curious as to motivation for 
>stretching raw scans.


Hi Joe,

It might not be the right answer though... <G>

You are right that a normal gamma curve would not be linear. I am only 
guessing as to why they would do this but I guess it's because negatives 
have inherently less contrast so they stretch it automatically. Why they do 
it to a "raw" scan, I have no idea.

Jerry

Astronomical photography: http://www.astropix.com




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