Canon EOS 90D Advanced User's Manual page 577

2: Adjust by Lens
You can make the adjustment for each lens and register the adjustment in the
camera. You can register the adjustment for up to 40 lenses. When you autofocus
with a lens whose adjustment is registered, the point of focus will always be
shifted by the adjustment amount.
Set the adjustment amount manually by repeatedly making adjustments, shooting,
and checking the results until the desired result is achieved. If you use a zoom
lens, make the adjustment for the wide-angle (W) and telephoto (T) ends.
(1)
Fine Adjustment of AF Position (AF Microadjustment)
1
Select [2:Adjust by lens].
2
Press the <Q> button.
3
Check and change the lens information.
Displaying the Lens Information
Press the < B > button to display the

lens name and a 10-digit serial number.
When the serial number is displayed,
select [OK] and go to step 4.
If the lens's serial number cannot be

confi rmed, "0000000000" will be displayed.
In this case, enter the number by following
the instructions on the next page.
Regarding the asterisk "*" displayed in

front of some lens serial numbers, see the
next page.
(1) Registered number
577