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2. Installation and Configuration
2.3 Varifocal Lens Back
The objective of back focusing
obtain the maximum far (wide) or tele (narrow) view from particular lens, back
be needed.
1. Choose an object at the farthest range
2. Make sure the iris of the lens is wide
lens at night or place a
environment.
3. Adjust the focus on the lens on its maximum
4. Adjust the zoom on the lens
5. Loosen the back focus lock screw.
6. Adjust the back focus ring for the clearest picture.
7. Tighten the back focus lock screw.
8. Repeat the previous steps as necessary to maintain a clear picture throughout the
entire zoom range.
2. Installation and Configuration
ack Focus Adjustment
The objective of back focusing is to suit different types of lenses that are in the market. To
obtain the maximum far (wide) or tele (narrow) view from particular lens, back
Choose an object at the farthest range.
Make sure the iris of the lens is wide open. Do this by adjusting the camera
place a welders glass in front of the lens to imitate the night
on the lens on its maximum “far” range.
Adjust the zoom on the lens on its maximum “wide” range.
Loosen the back focus lock screw.
Adjust the back focus ring for the clearest picture.
Tighten the back focus lock screw.
Repeat the previous steps as necessary to maintain a clear picture throughout the
is to suit different types of lenses that are in the market. To
obtain the maximum far (wide) or tele (narrow) view from particular lens, back focusing might
open. Do this by adjusting the camera and its
to imitate the night
Repeat the previous steps as necessary to maintain a clear picture throughout the