What's a dumb mistake you repeated for a long time without realizing it?

I've been shooting with my Fuji X100F for well over a year, and only just recently realized that I had my Noise Reduction settings backwards. I couldn't figure out why high ISO JPEG files looked so bad, and then last week I found out that setting my Noise Reduction to -2 was actually doing the opposite of what I thought it was supposed to. I set it to +2 and suddenly almost my high ISO shots looked much, much better. I couldn't believe I had gone so long without realizing this mistake and it makes me wonder what sort of similar things other people might have done too. via /r/photography http://bit.ly/2VbYlg6