Does MA improves sharpness and/or focusing problem?

Just received my sigma 85 last week. I did not notice any ff/bf problem as i tested it loosely. I have never tried MA before but if the lens has no focusing problem, does it improve on sharpness (especially in large aperture) if I look into MAing it?

MA corrects for not-accurate but precise focus. For example: the focus is consistently back focusing (focusing behind the target) you can adjust the MA so that it will focus on your target.
Remember though: For MA to correct, it must be consistently off in one direction or another (front focusing, focus is slightly in front of your subject; or back focusing, focus is slightly behind your subject).
Good Luck!

irukandji112 wrote in post #13384156
MA corrects for not-accurate but precise focus. For example: the focus is consistently back focusing (focusing behind the target) you can adjust the MA so that it will focus on your target.
Good Luck!

ic. Since mine focuses fine, i guess there's no need of me to MA it then.

You can have a lens that focuses perfectly but still lacks sharpness.

yogestee wrote in post #13384214
You can have a lens that focuses perfectly but still lacks sharpness.

If that is the case, bad copy?

kin2son wrote in post #13384269
If that is the case, bad copy?

Not always. Many lenses just by optical design aren't the sharpest at a certain aperture,, especially at full aperture.

kin2son wrote in post #13384129
Just received my sigma 85 last week. I did not notice any ff/bf problem as i tested it loosely. I have never tried MA before but if the lens has no focusing problem, does it improve on sharpness (especially in large aperture) if I look into MAing it?

usually but not always, in my experience it's rare to have a lens+body combo do best at 0, but you may luck out