AF Microadjustment
A camera setting that applies a per-lens correction to compensate for consistent front or back focus.
Measured in
steps (typically ±20)
In depth
The adjustment is stored against the lens's identity, so each body remembers its own corrections. Because focus error can differ between focal lengths and distances, better implementations allow separate values at the wide and long ends of a zoom. It is a workaround for a mechanical mismatch, not a fix for a genuinely decentred lens.
Examples in practice
Setting −7 on a fast 85 mm brings its focus plane back onto the target at every test distance.