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Here's another thing that's keeping me stuck using PS for the near future, as I haven't found a suitable replacement in another application...

I require precise adjustments of curves for when I create calibrated contrast correction for alt process photo printing. I regularly print using gum pigment (aka, gum bichromate), kallitype, gumoil and cyanotype techniques. The overwhelming majority of my fine art prints are done this way. To get the best results, it is necessary create compensation curves to correct for the deficiencies of the print process. They are all different, and ideally one would create individual curves for each kind of paper used, as well as for the different processes. I feel confident saying this is the common practice amongst alt process photo printers these days, so I'm certainly not the only one who would benefit.

A full description of the process I use can be found here: https://www.freestylephoto.biz/alternative-process/making-digital-negatives Please take special note of Figures H and I in the article because these illustrate exactly what I'm needing to do with curves.

What I need is the ability to precisely input the required I/O numbers into the curves dialog. Not only do I not see any way to do this in AP's curves, I don't even see any sort of scale that would clue me in to where I am on the curve. I am able to read gray values the way I need with the eyedropper, but without being able accurately translate those numbers to a curve, I'm stuck with only half the tools I need to do this.

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Also, lack of Gray Gamma 2.2 is annoying. I know that your Gray D50 claims to have a gamma of 2.2, but this still doesn't tell me whether it translates exactly to the same result as using Gray Gamma 2.2 profile.

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15 minutes ago, martinch said:

What I need is the ability to precisely input the required I/O numbers into the curves dialog.

I don't currently need this but I would really like to have it.


MacBook Pro (13-inch, Mid 2012) Mac OS 10.12.6 || Mac Pro (Late 2013) Mac OS 10.14.5

Affinity Designer 1.7.3 | Affinity Photo 1.7.3 | Affinity Publisher 1.7.3 | Affinity Designer Beta 1.7.x.x | Affinity Photo Beta 1.7.x.x | Affinity Publisher Beta 1.8.0.502

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I also want precision curve writing as I do corrections in LAB to take specific point (highlights, shadow, etc.) to specific values for certain papers. Using the picker doesn’t seem to work for the second point on the curve, but numeric input would be much easier even if the picker did work.

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Hello martinch and Old Bruce,

If it's of interest, I posted this method in the tutorials section of the forum:

It was tested on a 1.7.0 beta but it appears to work in current production 1.7.2.  Any comments would be appreciated.

Nigel

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