I was putting up some wall decorations earlier today and was painstakingly realigning everything until it looked level to my eyes. It might be just a hair off, but if I don’t correct it, I’ll see the misalignment almost instantly and get bothered for the rest of time until I fix it. Has anyone investigated, or is there literature on the minimum perceptible angle from level to the naked eye?
According to almost every photo I take, about 3 degrees off.
Pretty sure this is a psychophysics question, though I don’t know that field well enough to know what’s there.