I don't see a Photoshop problem here. With the gamma alone, why would you expect the values to remain the same? The lab values of the two (gray and Adobe RGB (1998) ) are the same when I view them before and after conversion (Lstar-0/4/5/710).
On Feb 12, 2022, at 7:31 PM, Peter Miles via colorsync-users <colorsync-users@lists.apple.com> wrote:
Hi List members
Adobe RGB (1998) is gamma 2.2. So I was surprised to see that Photoshop (2022 23.1.1) changed the RGB values of a step-wedge I made in Gray Gamma 2.2 space after I converted it into Adobe RGB space. For example, in Gray Gamma 2.2 space my wedge starts out with RGB values, 0,0,0 / 5,5,5 / 10,10,10 / 15,15,15 / 20,20,20…. and the AdobeRGB(1998) conversion goes 0,0,0 / 13,13,13 / 18,18,18 / 22,22,22 / 27,27,27…