U of S | Mailing List Archive | alt-photo-process-l | Re: uncurve/curve comparison on Loris' website

Re: uncurve/curve comparison on Loris' website


If I'm understanding your problem correctly, your curves are correct as
shown by a printed tonal palette but your prints are too dark?

If this is the case, it sounds like your monitor may have its brightness
setting up too high.  I would try lowering the brightness and then adjusting
the tonality of the image from there.  If your display is too bright chances
are you'll have a hard time getting a match between what's on screen and the

Camden Hardy


On 9/28/07 6:30 AM, "Loris Medici" <mail@loris.medici.name> wrote:

> Don,
> (1) I agree. My suggestion was assuming Chales doesn't want to go back
> to recalibrate each primary color individually but solve the problem
> pragmatically -> still using those curves. He says that his calibrations
> for each primary color is good -> if he does something wrong, that
> should be the pigment concentration... I don't know if it's enough to
> simply re-establish a new standart printing time when cutting back the
> pigment amount, but I feel like that won't be enough (= probably curves
> also will have to change). And if it's that way, then he'll need to go
> back to the long / laborious process of recalibrate... I would
> definitely try what I suggested and see if that gives satisfactory-to-me
> results. If yes, I would never go back to recalibrate since I'm more
> interested in making images instead of making images *in the absolutely
> correct way*. (Don't take it like I'm not interested in the latter at
> all, I just give more importance to be able to put my vision on
> paper...)
> (2) Yes indeed. But since Charles said that the only way of getting
> paper white with his printer (R1800) was using all inks grayscale
> negatives, I simply trust him. AFAIK, R1800 are not the best in the
> domain of UV blocking... That leaves him the only option of reducing the
> ES of his coating solutions (where available), which translates to "use
> less dichromate" and/or "use more pigment" in gum printing. Since we
> already suspect that his pigment concentrations are higher than what is
> needed, then using less dichromate looks like a sound advice to me.
> Regards,
> Loris.
> -----Original Message-----
> From: Don Bryant [mailto:dsbryant@bellsouth.net]
> Sent: Friday, September 28, 2007 3:05 PM
> To: alt-photo-process-l@usask.ca
> Subject: RE: uncurve/curve comparison on Loris' website
> Loris, 
> Charles if that also doesn't work, don't overlook my suggestion of a
> levels / gamma adjustment channel before making separations (in
> luminosity mode -> thanks Michael)...
> (1) I have to say, IMO that I regard this as a poor approach to solving
> the problem. Better to get the curves correct (if one is using curves).
> BTW, what dichromate concentration are you using? You may try to use
> less dichromate if you use saturated solutions. That way, you may
> achieve paper white with colorized negatives (despite their DR being
> lower compared to grayscale / all-inks negatives).
> (2) You can achieve paper white with saturated dichromate using
> colorized negatives.
> Don