BACKFOCUS MODE™
|
 |
BACKFOCUS
MODE™, A Revolution In Installation
Eliminate the hassle of backfocusing. No more filters or
numerous adjustments.
Rainbow's new cameras
now feature our exclusive BACKFOCUS MODE™ for a simple, one
touch backfocus procedure with auto-iris lenses.
Procedure:
- Push and hold the BACKFOCUS
MODE™ button. The lens iris will open automatically and
the Electronic Iris will turn on to prevent a washed out
picture.
- Adjust the lens for proper
focus. If the lens focus range is not sufficient, adjust the
focus screw on the side of the camera.
- Release the BACKFOCUS MODE™
button. The lens iris will return to normal and the
Electronic Iris will turn off. You're finished!
The camera and lens are now backfocused for proper day and
night operation.
|
Technically speaking:
The lens depth of field (focus) is
shortest during nighttime viewing when the iris is wide open. If the
lens and camera are not backfocused with the lens iris wide open, the
nighttime picture can appear out of focus. Since most installations
are performed during the day, the installer must drive the lens iris
wide open and use a filter or turn the electronic iris on temporarily.
Our BACKFOCUS MODE™ button eliminates the need to adjust the lens
level control and turn the electronic iris on.
When the button is pressed and held the
camera enters the following mode:
DC type lens:
Lens iris is driven to wide open
Electronic iris is turned on to compensate for the bright picture
Video type lens:
Video signal to lens is removed which causes most lenses to drive the
iris wide open
Electronic iris is turned on to compensate for the bright picture
The lens can now be focused for the
best nighttime picture.
When the button is released, the camera will return to its previous
state
(iris normal, Electronic Iris off)
|
