U of S | Mailing List Archive | alt-photo-process-l | Re: solarized gums?

Re: solarized gums?

Hi Loris,
You must have missed a crucial element of my point, if you think I'm recommending reducing or changing anything about the hue, DMax, or color saturation of the coating mix. I'm not recommending anything of the sort. I'm only saying that overpigmenting beyond the point where you've already reached the maximum DMax and color saturation for that pigment, can sometimes cause problems that can be remedied by backing off to a properly pigmented mix, without losing anything. If changing the pigment load changes the DMax or the color saturation, then you're not yet at maximum saturation, and by (my) definition, you're not in an overpigmentation situation. Changing an overpigmented mix to a properly pigmented mix doesn't change the hue or the density or the saturation or anything, since a properly pigmented mix is already at maximum DMax, density, hue, whatever, that the pigment is capable of. That's all I'm saying, so it seems like you're arguing against an argument I'm not making.

Other comments embedded below:

On Feb 15, 2007, at 1:10 AM, Loris Medici wrote:

Hi Katharine,

Apparently I had to use "tinting strength" instead of covering, thanks
for pointing that out.
Actually I don't like the term "tinting strength" and wouldn't use it, because it suggests something other than what I mean. I prefer "pigment strength" because it means not only that the color will overwhelm other colors in a mixture or an overlay, which is the meaning of "tinting strength" but also that doesn't take much pigment to achieve the maximum color saturation and DMax, even when the pigment is considered by itself without regard to other pigments it might be used with.

BTW, the pigment I used for that particular test
was same as yours, 15:3. I'm still insisting that it was a lightly
pigmented emulsion though... Anyway, I want to return to the main/ actual subject here: the remedy of
"tonal inversion". You suggest to reduce pigment/gum ratio in the
coating solution as the only remedy to the problem - that's what I'm
objecting to.
Point taken; we gum printers seem to have a natural resistance to categorical statements of any kind, don't we. I know it makes the hair go up on my neck if someone makes a categorical statement that I don't know to be true. If it will make you happier, I'll be glad to amend the statement on my website to read, "In my experience, reducing the pigment/gum ratio to a proper pigmentation is the way to remedy the problem," but that's as far as I can go. I can't say something that I haven't seen myself, and that I have yet to see convincing evidence of from others. I've never yet seen an example of a "tonal inversion" or any kind of stain that can unequivocally be attributed to exposure, and as my study of stain and exposure shows, I haven't been able to relate exposure to either stain in general or "tonal inversion" in particular. So it wouldn't make any sense to me to say on my website that changing exposure, or changing the DR of the negative, can eliminate "tonal inversion" since I don't know that.

And yes, I've experimented with using colored negatives to adjust the DR of the negative to the short range of the coating emulsion. I spent two months last fall lost down the rabbit hole of that gum curve thing, and would probably still be there, if I hadn't had a conversation with a very accomplished and knowledgeable photographer friend who spent quite a lot of time telling me I was crazy to be pursusing that line of inquiry and that I shouldn't change anything about the way I print gum. But nevertheless, during the time I was experimenting with that (and I made hundreds and hundreds of calibration prints, test strips and test prints; clothesbaskets full of test prints) I never once saw this "tonal inversion" that you say occurs with a 21-step but not with a negative color chosen to match the DR of the negative to the emulsion. And I'm also, although this is a different discussion, not convinced that adjusting the DR of the negative to the short range of the gum is the best way to handle the short range of gum.

Katharine