Installation guide

DVTel CF-4221-00 Fixed IP Camera User & Installation Guide
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7.6 Appendix F: 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
If the focus cannot be achieved within the zoom range, you may need to adjust the back-
focusing
To adjust back focus
1.) Set the Exposure Settings as follows:
a.) In the Web Base Viewer go to the Camera  Exposure screen and select from the
Exposure Setting menu Auto-shutter mode.
b.) Save changes
Tip: It is preferably do the adjustment during low light conditions.
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 75 feet, 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.