Digital BW, The Print

> 
> I hope you will persevere with me on this and I hope people like Roy are
> listening in.
> 
> Like that LAB!
> 
> Steve
> 

Hi Steve,

I've actually been following the thread all along and it sure has sparked a
lot of interesting questions.

I like comparing things and linearizing in Lab because it's supposed to the ideal
match for human vision.  I.e. linear Lab ought to be linear visually -- in other
words a difference from Lab 15 to 20 (5%) is comparable to a difference from
Lab 50 to 55 (also 5%) and Lab 85 to 90.  This makes sense as the best use of
the 256 values you get for an 8bit data file.

Unfortunately Photoshop doesn't have a Lab oriented grayspace.  We could use
Lab spaces but first they have 3 channels so your files will be triple the size with
no more info.  Second I think when you print, PS will get you "out of Lab" in the
conversion to grayscale doing a profile mapping for you (or is it to you :) ).

The main reason I've always used gray gamma 2.2 along with adobe RGB is that
with the eye dropper you can see the 8 bit values in the file.  K gives only 0-100
but underneath its really 0-255. You can see 0-255 in the RGB values but they
are only correct if the gray and color spaces have the same gamma. (Profile
conversions are always going on).


Roy