Campbell CCFC Instruction Manual - page 96
CCFC Field Camera
A-1
When the IR LEDs are enabled, the camera will automatically
switch them on and off during photo or video capture when the
ambient light level drops too low. Generally, this happens shortly
after sunset outdoors. The IR LEDs remain on while the camera is
awake. If the camera is configured to use a low power mode, the
IR LEDs will turn off when the camera goes to sleep.
The IR LEDs and the lens defroster are multiplexed together, so
only one will operate at a time. In a situation where both the IR
LEDs and the defroster should be on, the IR LEDs take priority as
they also provide a significant amount of heat to the lens.
The IR LEDs emit light at 850 nm wavelength in a 12° cone from
the centerline. This is a fairly narrow beam angle, which
concentrates the light on the center of the photo, allowing distant
objects up to 36m (120 ft) away to be illuminated.
12.8.4.4.2
Filter Control
Outdoor photos contain a great deal of IR light from the sun. The
photo sensor in the CCFC is sensitive to this IR light and will pick
it up causing the photo to look improperly colored. The lens on
the CCFC is equipped with a switchable IR filter to counteract
this effect.
The setting for the IR filter allows it to be enabled all the time or
disabled when the camera is in night mode, giving the camera
extra sensitivity in dark scenes without having to use the IR
LEDs.
When the IR LEDs are enabled and switched on, the IR filter
automatically switches off regardless of the IR filter setting.
12.8.4.4.3
Light Power Control
The Power Control wire can be used to control an external light
source or a relay that activates an external light source. The
camera can be configured to switch the external 12 Vdc (yellow
wire) on, based on the available light in the scene.
The light will only come on when capturing from a timed capture
or when an external trigger occurs while the camera is in sleep
mode. The light does not turn on for motion detect capture. The
light turns off after the capture is complete.