Joao Ribeiro (jribeiro@greco.com.br)
Fri, 05 Mar 1999 23:27:02 -0300
Hi Dave,
I know you are busy so reply when you can.
> Say if you have a short-range negative.
No, it's a long range one.
> But that is assuming the density range of your original negatives is within
> this 7-8 steps mentioned above. If this is true, then you can cover the whole
> thing with exposure only without flashing (as you also suggested yourself). If
> the density range of your negative is high, however, when you expose more to
> get better highligh separation, you start to lose shadows, and vice versa.
So the best solution would be a weaker first developer, or not?
> Since I have talked with you about densitometry, I am assuming you are
> familiar with film's curve, the typical S curve.
Yes, I am
> Now if the density range of your negative is longer than the exposure range of
> lith film, you cannot cover the whole range, therefore you can use flashing to
> help. However, flashing ***does not change overall contrast***. It only raises
> the contrast of the low-density area (highlights of positive or shadows of
> negatives) a little so that you can have better separation.... better compared
> to the flat toe; but this is not the same thing as putting the highlights into
> the linear region of the S curve.
So I will control the Y axis (densities in the lith film) range a little but won't
change the X (steps in the original) to Y relationship too much. Is that it?
What I need is to decrease gamma value if I am understanding.
> There are other possible solutions if you have long-range negatives, but
> that's the part that I said I would get to later.
So I'll wait :)
Cheers
Joao
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