Back-Focus Adjustment - JVC VN-C10U - Network Camera User Manual

Preparations (Step 3 Adjusting the Camera)

Back-focus Adjustment

At the factory, back-focus is set at the point for the widest range of use for
CS-mount. However, it is necessary to readjust back focus if a zoom or C-mount
lens is used or if focus cannot be attained using the focus ring of the lens. To
adjust, follow the procedures described below.
In order to adjust back-focus appropriately, use the iris adjustment function and an ND filter to re-
lease the lens iris before proceeding with the adjustment. (An ND filter acts to reduce the overall
amount of light entering the lens equally over all wavelengths.)
Back focus
adjustment ring
Loosen
Lens focus ring
24
Tighten
Back focus locking
screw (M2.6)
<For a fixed-focus lens>
If focus cannot be attained using the focus ring of
the lens, adjust the back-focus as follows.
1. Loosen the back-focus lock screw by turning
it counterclockwise with a Phillips screwdriver.
2. Aim the camera at the object or a spot of detail
somewhere away from the object while
checking the image on the PC screen.
3. Turn the focus ring to .
4. Turn the back-focus adjustment ring to
optimize the focus.
5. Tighten the back-focus lock screw securely by
turning it clockwise.
<For a zoom lens>
If the image gets out of focus when zoomed in/
out, adjust the camera as follows:
1. Loosen the back-focus locking screw by
turning it counterclockwise with a Phillips
screwdriver.
2. Aim the camera at the object or a spot of detail
somewhere away from the object while
checking the image on the PC screen.
3. Zoom in the lens and adjust the focus by
turning the focus ring.
4. Zoom out the lens and adjust the focus by
turning the focus ring.
5. Repeat steps 3 and 4 a few times.
6. Tighten the back-focus locking screw securely
by turning it clockwise.