FLIR SR-124 Installation And Operation Manual page 23

Performance varies with time of day
You may observe differences in the way the camera performs at different times of the day, due
to the diurnal cycle of the sun. Recall that the camera produces an image based on temperature
differences. At certain times of the day, such as just before dawn, the objects in the image
scene may all be roughly the same temperature, compared to other times of the day. Compare
this to imagery right after sunset, when objects in the image may be radiating heat energy that
has been absorbed during the day due to solar loading. Greater temperature differences in the
scene generally will allow the camera to produce high-contrast imagery.
Note: Under conditions such as just before dawn when it appears the camera has low contrast
due to many objects at roughly the same temperature (typically inanimate objects), a person or
an animal walking through the scene during this time will be quite noticeable and cause the
AGC to produce a high-contrast image.
Eastern or Western Exposure
Some users will choose to mount the camera pointing directly east or west, and this may cause
the sun to be in the field of view during certain portions of the day. We do not recommend
intentionally viewing the sun, but looking at the sun will not permanently damage the sensor.
However, it may cause image anomalies and it may take some time for the camera to recover.
The amount of time needed for recovery will depend on how long the camera was exposed to
the sun. The longer the exposure, the longer the recovery time needed.
Image freezes
By design, the camera image will freeze momentarily on a periodic basis during the Flat Field
Correction (FFC) cycle. Refer to section 5.4 Flat Field Correction (FFC) for more information
about this. It is possible to change the interval used for FFC with the FLIR Camera Controller
GUI; refer to the Tau User's Manual for more information.. The software is included in CD form
with the SR-Series camera, but can also be downloaded at:
http://www.flir.com/cvs/cores/resources/software/tau/.
427-0042-00-10 Revision 130 Copyright © 2011 FLIR Systems, Inc. 23