Axis Communications 2120 - Manual (Page 49)

AXIS 2120 User’s Manual Adjusting the Camera Focus 49
Adjusting the Back Focus
Your AXIS 2120 is supplied with the back focus roughly set to accommodate a reasonable level of
focus throughout the complete focusing range. However, if you are using a lens other than that
supplied with your product - or you are dissatisfied with the quality of focusing at a specific plane
(or at several planes) within the focusing range, you may need to make some fine adjustments to
the back focusing of the lens. This is performed by adjusting the focus and zoom rings of the
camera lens, as described below:
Procedure
1. With the Focus Ring set to the Far-focus (F,
∞
) position, aim the camera at a subject over 30
metres away.
2. Set the lens assembly to wide angle, and adjust the back focus by loosening the Lock Ring and
then turning the lens assembly. Continue to turn the lens assembly until you achieve optimum
image clarity
3. Check that you obtain sharp pictures at various zoom grades and various distances.
Note: If possible, it is better to perform this adjustment in low light conditions, or with a filter covering
the front optic. This will ensure the iris is fully open to give the smallest depth of field, and there-
fore the best results.