Save read and write Curves

[Richsul]

Folks,

There are thousands of photographers making platinum prints, palladium, gum, oil prints, resinotype, cyanotype, etc. 

Originally these were historic processes and were made via contact negative. Today, we use a digital negative made in a digital printer. Each process, needs a negative, and the negative needs to be corrected for the process's formula, paper, climate conditions (Key West vs Santa Fe,) and printer and inkset, (Matte Black vs Photo Black,) or RGB, vs grayscale.) Making a curve is tedious and we share them, At Bostick & Sullivan, at Photrio, Alternative Photography, and so on. Many are switching over to Affinity, my favorite too... but... we have to keep a subscription to Photoshop to be able to apply to make a negative on Pictorio. This is nice for Adobe, but not to Affinity's users.

We need to be able to read a ACV correction curve and apply it to a digital image before printing. This is because most of these processes are printed using the blue and near UV spectrum and various inks transmit UV light in a non linear fashion. For instance a tiny amount of yellow increases contrast.

We are in need of Affinity:

Being able to read and apply a ACV curve from Adobe,

Or convert and existing ACV curve to an Affinity curve.

Or at least be able to create a curve in Affinity.

This is done by printing a step wedge and scanning the print and coming up with a correcting value and building a new curve from the corrected values.

A sample curve created this weekend is attached.

Thanks.

-- Dick Sullivan HonFRPS
Honorary Fellow of the Royal Photographic Society
www.bostick-sullivan.com
Santa Fe, New Mexico

 

10%pt_AFOplatinumprintcurve.acv Untitled-1.tif