Adjusting Back Focus - JVC LST0904-001B Instruction Manual

Adjusting Back Focus

When the lens is first attached, adjust the back focus of the
lens if the focus is not clear when zoomed to the telephoto or
wide angle end.
● Place an object 3 m and above away from the camera.
● The Siemens Star Chart is most suitable as the object.
3 4, 6
Siemens Star Chart
5
1
M
2 7, 8, 10
1
Set the iris mode switch of the lens to M (manual).
2
Set the zoom mode switch to MANU. (manual).
3
Turn to open the iris ring.
Adjust the lighting such that the optimum image level can be
obtained.
4
Turn the zoom lever to set the lens to the maximum
telephoto position.
5
Turn the focus ring to adjust the focus of the object.
6
Set the lens to the maximum wide angle position.
7
Loosen the lock screw of the back focus ring.
8
Shoot the same object and secure the back focus ring
at the position where the object is in focus.
9
4 8
Repeat steps to three times until the object is in
focus at both the telephoto and wide angle positions.
10
Tighten and secure the lock screw of the back focus
ring.