I’ve recently bought a decent camera lens and decided to check its quality. I used camera targets for this purpose, thanks to fotosav.ru for them.
1. Shooting mira for peripheral sharpness test.
I printed four A4 sheets, stuck them together and photographed.
At f2.8 it was sharp as it’s supposed to be, but f16 and 32 made me a bit surprised. I expected crisper photos at smaller holes, but the result was opposite.
I thought the lens is bad and went to get something from Google, which said it’s normal. This is just a result of diffractions.
Here’s the discussion about it.
2. Autofocus target.
Make sure squares are facing your camera perpendicularly.
The result is predictibly good.