Auto Exposure - FLIR GRASSHOPPER 3 Series Technical Reference

To adjust gain:
GenICam—Analog Control
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To access negative Gain values—From Remove Parameter Limits, select Gain and set Remove
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Limits to True.
FlyCapture
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8.11

Auto Exposure

Auto exposure allows the camera to automatically control exposure and/or gain in order to achieve a specific
average image intensity. Additionally, users can specify the range of allowed values used by the auto-exposure
algorithm by setting the auto exposure range, the auto shutter range, and the auto gain range.
Auto Exposure allows the user to control the camera system's automatic exposure algorithm. It has three useful
states:
State
Off
Manual Exposure
Control
Auto Exposure Control
Auto Exposure can only control the exposure when Exposure and/or Gain are set to Continuous. If only one of the
settings is in "auto" mode then the auto exposure controller attempts to control the image intensity using just that
one setting. If both of these settings are in "auto" mode the auto exposure controller uses a exposure-before-gain
heuristic to try and maximize the signal-to-noise ratio by favoring a longer exposure time over a larger gain value.
The auto exposure algorithm is only applied to the active region of interest, and not the entire array of active pixels.
There are four parameters that affect Auto Exposure:
Auto Exposure Range—Allows the user to specify the range of allowed exposure values to be used by the
automatic exposure controller when in auto mode.
Auto Shutter Range—Allows the user to specify the range of exposure values to be used by the automatic
exposure controller which is generally some subset of the entire exposure range.
Auto Gain Range—Allows the user to specify the range of gain values to be used by the automatic exposure
controller which is generally some subset of the entire gain range.
2/10/2017
©2013-2017
FLIR Integrated Imaging
Solutions Inc. All rights reserved.
Note: Increasing gain also increases image noise, which can
affect image quality. To increase image intensity, try adjusting
the lens aperture (iris)
API—Setting Gain Using the FlyCapture API
Control of the exposure is achieved via setting both Exposure and Gain. This mode is
achieved by setting Auto Exposure to Off, or by setting Exposure and Gain to Off.
The camera automatically modifies Exposure and Gain to try to match the average image
intensity to the Auto Exposure value. This mode is achieved by setting Auto Exposure to
Off and either/both of Exposure and Gain to Continuous.
The camera automatically modifies the value in order to produce an image that is visually
pleasing. This mode is achieved by setting the all three of Auto Exposure, Exposure, and
Gain to Continuous. In this mode, the value reflects the average image intensity.
Grasshopper
andExposure Time time first.
Description
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3 PGE Technical Reference
8 Grasshopper3 PGE Attributes
73