Back Focus Adjustment - Quasar CF-3211 User And Installation Manual

Quasar CF-3211/CF-4221 User and Installation Guide
A.7. Back Focus Adjustment
When to adjust back focus
Back focus refers to the distance from the rear lens element to the camera focal plane. In most
cases, it is required to adjust back-focus only when the camera's lens cannot hold focus throughout
its zoom range. If the focus cannot be achieved within the zoom range, you may need to adjust the
back-focus.
Requirements:
Tools required when carrying out back-focus adjustment include:
o Back focus adjuster (in the IP camera's package)
o Test chart/contrasting object
To adjust back focus:
1. Set the Exposure Settings as follows:
a. In the Viewer, select the Camera tab.
b. From the Exposure menu, select Auto Shutter mode. See section 7.5.1, Exposure.
c. Click the
2. Do the following:
a. View an object at least 75 feet (23 meters) away. For greater telephoto capable lenses,
the object can be located further away. If the field of view is less than this distance, the
object should be as distant as possible.
b. Adjust the zoom to the extreme telephoto position.
c. Adjust the focus to the best possible focused image.
d. If the image is not focused (sharp), loosen the back-focus ring retaining screw with the
supplied hex tool and rotate the lens mount to adjust the back focus as needed to
achieve a sharp picture in focus.
110
icon to save changes.
Tip:
It is preferable do the adjustment during low light conditions.
Figure 99: Back Focus Adjustment