Originally posted by Marc Sabatella Tiny amount, yes. Enough to yield OOF images at the target point at f/2.8?....
.
By f/2.8, the increasing DOF is going to help hide any tiny problems that might
exist. By f/4, and shooting at a distance, they could be hidden altogether.
The problem comes up when you want to shoot at f/1.4, 1.7 or f2, and you notice
that your 'critical sharpness' is missing - you have the option of sending the lens
back, even though it's giving you good results at f/2.8+, or adjusting a small
amount with in-body AF adjust.
Personally, I'd rather keep an 'in spec' lens and make it spot-on than send it
back, try another, test, repeat... until I got the perfect copy. Not when I can
make it 'perfect' myself.
If I have a lens that's giving me noticeable FF/BF at f/4, it's going back. If I have
2mm of FF at f/1.7, I'd like the option to tweak AF. It's an important feature for
me, especially after having shot with my D90 for a while now - I have a couple
very sharp, contrasty lenses in Nikon mount that would be
perfect with AF adjust...