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DCx camera
© 2010 Thorlabs
9.6
Gain and offset
Digital image sensors sum up electrical charge proportional to the amount of incident light. The
signal can be amplified directly on the sensor in order to increase the contrast of the image output
(hardware gain). An offset can be set in order to adjust the brightness of the image (blacklevel). The
results of the analogue signal processing are usually better than the results of digital post-
processing.
9.6.1
Hardware gain
Analogue amplification of read out pixels increases the overall image brightness and contrast.
Depending on the sensor type a global gain value for all pixels (master gain) or a separate gain value
for every color (RGB gain) can be set.
HINT
Using the sensor hardware gain also increases image noise.
It is not recommended to use high gain settings.
9.6.2
Offset (Black level)
Digital image sensors own light insensitive cells next to the active image area. These dark pixels are
used to measure a reference voltage (blacklevel) which is subtracted from the image signal. This
compensates thermally generated voltages which would otherwise falsify the signals. Normally the
sensor adjusts the blacklevel automatically, but the blacklevel value can also be manually adjusted.
9.7
Readout of relevant image areas
Each Camera sensor has a defined resolution determined by the number of horizontal and vertical
pixels (e.g. 1024 x 768 pixel). However for some applications it may be necessary to read out only a
certain subarea of the sensor. For this purpose DCU cameras offer different functions:
Area Of Interest (AOI)
Binning (combining) of pixel
Subsampling (skipping) of pixel
With these methods the volume of data to be transmitted is reduced. Therefore higher frame rates
can be achieved. Cameras with CCD sensors achieve higher frame rates with reduced image height.
Reducing image width has no effect on the possible frame rate.
9.7.1
Area Of Interest (AOI)
The sensor AOI function makes possible to specify the size and position of sensor area. Only the
data of this area will be read out and transferred to the PC. With a smaller image area higher
camera frame rates can be achieved. After specifying an AOI a new value for the exposure time can
be set.
Summary of Contents for DCC1 45 Series
Page 5: ...Version Date 3 5 2 22 09 2010 2010 Thorlabs 2010 Thorlabs ...
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Page 16: ...Introduction DCx camera Part I ...
Page 18: ...General Information DCx camera Part II ...
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Page 22: ...Getting Started DCx camera Part III ...
Page 24: ...Installation DCx camera Part IV ...
Page 30: ...uc480 Camera Manager DCx camera Part V ...
Page 38: ...Camera viewer uc480Viewer DCx camera Part VI ...
Page 45: ...40 DCx camera 2010 Thorlabs Menu Help Figure 15 Info about Camera viewer uc480Viewer ...
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Page 88: ...SDK Software development Kit DCx camera Part VII ...
Page 109: ...104 DCx camera 2010 Thorlabs Figure 52 Flowchart Handling events messages ...
Page 121: ...116 DCx camera 2010 Thorlabs Flowchart Digital output Figure 57 Flowchart Digital output ...
Page 161: ...156 DCx camera 2010 Thorlabs Related Functions is_GetCameraType is_CameraStatus 159 121 ...
Page 175: ...170 DCx camera 2010 Thorlabs is_GetExposureTime 167 ...
Page 238: ...233 SDK Software development Kit 2010 Thorlabs is_SetImagePos is_SetPixelClock 271 277 ...
Page 261: ...256 DCx camera 2010 Thorlabs is_SetTriggerDelay 289 ...
Page 271: ...266 DCx camera 2010 Thorlabs is_SetGainBoost is_SetAutoParameter 261 221 ...
Page 283: ...278 DCx camera 2010 Thorlabs is_SetSubSampling is_SetAOI 284 219 ...
Page 291: ...286 DCx camera 2010 Thorlabs is_SetAOI is_SetImagePos is_SetPixelClock 219 271 277 ...
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Page 362: ...Maintenance and Service DCx camera Part VIII ...
Page 370: ...365 Maintenance and Service 2010 Thorlabs ...
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Page 372: ...Camera Basics DCx camera Part IX ...
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Page 390: ...Appendices DCx camera Part X ...
Page 397: ...392 DCx camera 2010 Thorlabs Figure 90 Securing the adjusting ring ...
Page 405: ...400 DCx camera 2010 Thorlabs Figure 106 Rev 2 0 Flash Strobe output as Open Emitter OE ...
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