THORLABS DCU223x Operation Manual And Sdk page 66

DCx Cameras
adjusted to the origin with the offset control before the measurement is done.
Color sensor
The color sensor's black level cannot be adjusted manually, as the RGB gains are downstreamed and an
adjustment would cause color errors.
Automatic black level correction is always enabled.
The RGB gains work analog.
The fast line scan
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NIR sensor
It is recommended to use a IR-coated and IR-corrected high-quality lens, especially for non-monochromatic light.
In the high IR wavelength range picture blur can occur with strong contrasts. This reduced MTF (modulation
transfer function) is a characteristic of the sensor pixels.
The master gain of the NIR sensor is adapted in comparison to the monochrome sensor. If both sensors are
compared directly, the gain of the NIR sensor must be set to the double factor of the monochrome sensor. This
can be done via the master gain or the gain boost.
In the Log mode the guaranteed dynamic range of the NIR sensor is reached with a gain value of at least 1. For
the monochrome sensor you need at least a value of 3. With very short exposure times, lower values can result
in even higher dynamics.
Gain, pixel clock
Master gain uses a combination of coarsely scaled analog gain factors and finer digital scaling. To achieve
optimum homogeneity of the gray level, use only the gain factors 0, 33, 66, and 100.
The gain boost has the factor 2. When using the master gain a maximum factor of 8 is possible caused by the
sensor.
For global shutter mode the pixel clock should be set to the maximum possible value to increase the image
quality.
In the 10 bit mode the usage of the digital gain intermediate level produces missing pixel values as the sensor
works internally with maximally 10 bit.
Hot pixel
In the rolling shutter mode, there are less hot pixels, as the pixel charges are not buffered in the sensor.
The sensor corrects hot pixels dynamically. Neighboured hot pixels in diagonal direction cannot be corrected
effectively. These positions are covered by the factory-made hot pixel correction and are eliminated by the
software hot pixel correction. Therefore, the hardware hot pixel correction is a prerequisite and should not be
deactivated.
On the color sensor the hot pixel correction works with the appropriate color neighbours.
In the global shutter mode, increased hot pixels can become visible in the lower image area with log exposure
time, a high gain and disabled hot pixel correction.
Both hot pixel corrections should be disabled if extremely fine structures are captured with a high-quality lenses.
For the measurements of noise characteristics both hot pixel corrections should be disabled.
The activation of the factory-made hot pixel correction reduces the frame rate slightly. Here, the desired frame
rate has to set after the activation or deactivation of the factory-made hot pixel correction.
Increased hot pixels can occur In the entire image border area.
Binning
2x binning makes the image brighter by a factor of about two. It also reduces image noise.
Binning does not result in a higher frame rate. Using binning allows higher pixel clock frequencies for USB DCx
cameras with the USB 2.0 and GigE interface. To achieve the maximum frame rate, activate first the binning and
then change the maximum pixel clock frequency.
When using binning the frame is slightly shifted horizontally.
Binning can only be enabled for both horizontal and vertical pixels. For this reason, the parameters of the
is_SetBinning()
IS_BINNING_2X_HORIZONTAL) to enable binning.
Scaling, AOI
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mode is disabled.
function have
310
to be passed together (IS_BINNING_2X_VERTICAL
© 2013 Thorlabs GmbH
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