Re: Two tricolor prints
Katherine, Part of the problem is that I posted to the wrong thread regarding your curve. I believe it was your post below that I was referring to. It sounded as if the curve you had calibrated for gum was giving you flat midtones in order to get separation in the shadows and highlights—as were examples that others had sent to you. I was asking if you could send the curve you were working on or post it so that I could see more clearly what you are talking about—often the shape of the curve will tell you a lot about what is going on. Best Wishes, Mark Nelson Precision Digital Negatives - The System PDNPrint Forum at Yahoo Groups www.MarkINelsonPhoto.com In a message dated 9/26/07 10:54:34 AM, kthayer@pacifier.com writes: Yes, but the overall low contrast is to some extent an inevitable result of setting the density of the negative to match the scale of the gum, which was part of my point. There's so much difference to be made up that it's very difficult to find a curve that will replace the contrast that you've lost, if that makes sense. If you have any slope through the midtones, then you sacrifice separation in the highlights or shadows or both. If you get separation in the highlights and shadows, then your midtones have to be flat. So far, I haven't found a curve that makes a better gum print than a diagonal line does (for my printer, light, negative media, etc) but I haven't given up yet. I would think maybe I was missing something (which is entirely possible, since while I'm generally thought of as a fairly intelligent person and mastered statistics with no trouble, this stuff just makes no sense to me at all) except that a number of people have thoughtfully sent me calibration charts and curves to show me how I "should" be calibrating my curves for gum, and these have shown the same difficulty I'm struggling with. For one thing they have been made with underpigmented mixes, which I find interesting and somewhat inexplicable, but the main thing is that the post-curve step tablets seem to follow the same pattern: say in a 101-step chart, the steps from 1-10 or so show nice gradation, and the steps from 85 or 90 to 100 show good gradation, but all the steps from 15-85 are the same tone. And the curve reflects that exactly: a slope in the highlights and shadows, but horizontal through the midtones. Or, they have to lighten the highlights too much in order to leave room for a slope in the midtones. No matter what you do, something has to give. So I'm still struggling with that fundamental difficulty with making curves for gum. ************************************** See what's new at http://www.aol.com |