Canon CN-E30-300mm T2.95-3.7 L SP - Manual (Page 19)

6 7
F.B. (Back Focus) Adjustment
F.B. (back focus) of this lens can be adjusted in the following procedures.
Before starting, select an object with sharp contrast at a distance* that facilitates the
adjustment work.
* Recommended object distance range: 6 to 12 ft.
1
Remove three screws
and remove the F.B.
adjuster cover as in the
right figure.
Note: Be sure to keep the
screws for later reattachment.
2
Mount the lens on the
camera and turn two
F.B. adjuster screws
counterclockwise one
revolution as in the right
figure.
CAUTION
Be sure to securely mount the lens on
the camera mount.
Note: Be sure not to remove
the screws.
F.B. adjuster
cover
Screws x 3
360 degrees
Screws x 2