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

Re: uncurve/curve comparison on Loris' website

Sorry, the more I think about this the more it seems like watching a dog chasing its tail. You start out with a (black) negative that prints too contrasty because there's too much density at the top end of the scale. To eliminate that problem, you make a colorized negative with a lower DR. But if the color/curve takes out too much density so you're getting tones where you don't want them, then you decrease the dichromate to increase the contrast so that the lightest tones won't stick. This seems like a merry-go-round that one might never get off of.

On Sep 28, 2007, at 7:28 AM, Katharine Thayer wrote:

On Sep 28, 2007, at 1:50 AM, Loris Medici wrote:

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).

Mmm, I have to disagree with this. If the color is right, there should be no difficulty getting paper white if the negative is calibrated properly. I get paper white all the time with colorized negatives and saturated ammonium dichromate. The purpose of the colorized negative/lowered DR is to eliminate the extra headroom in the white, but if you don't get any white at all, something's wrong (my example Exhibit A). After all, one calibrates with the mix one is using, so it doesn't make sense if the negative the calibration produces doesn't work for the mix one is using.