Jul 1, 2024
Monitor gamma 2.2 adjustment test images, screenshot from the Gamma 2.2 pop-up window linked from http://www.photoscientia.co.uk/Gamma.htm
I've always eyeballed these to calibrate my monitor roughly for graphics work. Also set Photoshop to gamma 2.2 in its options. There are other ways to do it--that's just what I do.
Wikipedia has a pretty good page on this, with their own test image: https://en.wikipedia.org/wiki/Gamma_correction#Simple_monitor_tests