Specs
Features
MTF
Tried one not long ago. Image was good, focus also worked not so bad.
Review
In short - lens is good and sharp, but AF is slow and noisy.
https://petapixel.com/2017/10/18/review-yongnuo-40mm-f2-8-pancake-lens-nikon-bad/
It looks like you're new here. If you want to get involved, click one of these buttons!