[Alt-photo] Re: GUM: problematic yellow?

[Alberto Novo]

Yes for the minimum exposure time (the value which gives you the maximun 
"black" without merging steps 1&2). But if you will find that the amount of 
color is too much or too less, and you will be forced to modify the % of 
pigment in the mix, you have to find the new minimum exposure time because 
the pigment itself acts as a self-mask to UV. This depends on the pigment 
and cannot be generalized (UV absorption is independent on visual density). 

Alberto 

>  
> I think that when I start layering the colors I will have to make other
> adjustments, either to the exposure time, color mix, or negative. But for
> now I was wondering if for blue I should use an exposure of 2 minutes (as
> indicated by looking at the color page) or 3 minutes (as indicated by
> looking at the grayscale version). In summary, are you suggesting that is
> best, as a starting point, to evaluate the exposure time by looking only at
> the grayscale version? 
> 
> Luciano