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9. Exposure Control
FrogEye’s overall exposure control system is designed to produce best available detail even under difficult conditions
such as haze or when imaging a moving target in low light conditions. To control exposure, select your operating mode
by choosing
Gain
and
AE (Auto Exposure)
options from the control menu
.
Set the lens
Aperture
as needed. When
imaging, activate the
Exposure Control
and use the CB1 & CB2 buttons to tune exposure for best effect.
Gain
The digital gain function on the control menu controls how the camera regulates image brightness and contrast.
•
AUTO
gain is recommended for most situations. The camera regulates both image brightness and contrast
independent of exposure time and aperture
. With AUTO gain, you can operate within a wide exposure range
while maintaining good brightness. For example, image a twilight scene at 1/10 second exposure to best
reproduce shades and colors of static objects, or shoot the same scene at 1/1000 second exposure time to
‘freeze’ and recognize moving vehicles and people.
AUTO
mode also regulates contrast, making the darkest spot
in the image black while making the brightest spot white. This improves the detection of recognition of details in
foggy or hazy conditions. However, the resulting high contrast also highlights defects such as smudges on the
lens or image sensor noise.
•
Setting
x1 to x8
are fixed digital gain settings, similar to choosing a film speed in a traditional camera. Going
from x1 to x8 increases image brightness eightfold. The image will become darker or brighter when you shorten
or lengthen the exposure time. Use a fixed gain to produce an image with most accurate contrast and colors.
Motion blur control with AUTO Gain: 1/64 sec exposure (left) and 1/1500 sec exposure (right)
Contrast Enhancement with AUTO Gain: GAIN=x1 (left) and GAIN=AUTO (right)
