As I was working on separating some dark tones on some new images this morning, I pulled up a grayscale tester I made a while back. Not that there aren't a lot our there, but I haven't seen any quite like this and thought some of you might find it interesting and/or useful.
The tester has bars of different gray values withnumbers printed over them. The numbers represent the r, g and b values of that number and go up by 2s. For example, the first bar, "0," has r, g and b values of 0,0,0 (pure black) and has printed over it numbers from 0 to 40; the "2" has rgb of 2,2,2 the "4" rgb of 4,4,4 and so on.
I find this a bit more informative than step scales and gradients as you can see more than one level against another and also know the actual rgb value.
My new, calibrated NEC 3090 monitor shows + and - 2 ok until the ends of the scale. At the white end it's about +/- 4, and near pure black, 8 is the lowest number I can distinguish on a 0,0,0 bar. When I print (custom profile), one of the more interesting things (at least to me
is the difference lighting makes. In normal gallery light, the lowest number I can see on pure black is 14, however, in bright sunlight, I can see 6. Similar, but smaller, differences exist at other values. Not too surprising, I suppose but a reminder that you have to print for the destination lighting.
Anyway, I've attached a jpg of it for those who might want to play. I don't cover the full grayscale (it was a bit annoying to make, plus I figured the main issues would arise at the ends of the scale).
Rob P