Digital BW, The Print

I don't necessarily try to make the channels add up to 100; I
generally watch the histogram if I am trying to get a "full range" of
gray values.  It tells you what the actual distribution of the values
is.  You easily check to make sure that you do not truncate your data
on either end in this manner.

Of course, you might not always *want* your values to span from 0 to
255...but I often start this way and then adjust as desired.

Just my $.02... 8*)

Eric

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, Walt Farrell
<wftemp1@h...> wrote:
> Steve Kale wrote:
<snip...> 
> Perhaps I'm still not understanding something, but I'm not convinced 
> that making the numbers add up to 100% will necessarily keep the 
> luminance the same.
> 
> Consider an image that was pure red.  Using your numbers above, you
keep 
> 50% of the red value and don't add anything else because there is no 
> blue or green.  At that point your image would (I would think) have
only 
> half the luminance of the original.
> 
> 	Walt