First Light C-RED 3 - Bias;Flat Correction; Legacy Bias;Flat Computation; Bias;Flat Computation

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Bias/Flat Correction
Bias/Flat correction can be done on the fly by the camera.
Building bias correction requires to put the camera in the dark.
Building flat correction requires to put the camera in front of a flat field.
Flat and Bias correction files can be computed automatically by the camera. Alternatively, custom
correction files can be uploaded to the camera using serial connection (either USB or CL) or using
TCP/IP connection.
The bias correction is the second correction applied on pixel values read from the sensor.
The flat correction is the third correction applied on pixel values read from the sensor.
Even if it is possible to activate the different corrections independently from each other, it is important
to understand that the correction will depend from all previous corrections applied.
For example, a bias correction file generated with bad pixels correction enabled will not be valid if bad
pixels correction is disabled.
Flat correction should always be used with bias correction enabled.
On firmware versions 1.3.0 and above, it is no longer possible to enable the flat correction if the bias
correction has not been enabled first. Also, disabling the bias correction automatically disables the flat
correction.
Bias and flat corrections also depend from the acquisition parameters (frame rate, integration time,
sensor temperature…). It is highly recommended to rebuild them when acquisition parameters are
modified.
To enable/disable the bias correction, use the command: “set bias on” or “set bias off”
To enable/disable the flat correction, use the command: “set flat on” or “set flat off”
Legacy bias/flat computation
Computation of bias and flat correction computation are initiated using “exec buildbias” or “exec
buildflat”, “exec buildflat hdr_c1” and “exec buildflat hdr_c2” on the command line
interpreter.
The frames used to compute the bias and flat correction are grabbed for 2s up to 256 frames.
With low framerate, not enough frames are grabbed, and the embedded bias/flat computation mustn’t
be used.
Bias/Flat frames must be computed outside the camera and uploaded on the camera.
Automatic computation of bias and flat correction files is only possible if the frame rate is above 5 fps.
bias/flat computation
Firmware 1.1.0 introduces a new set of commands that supersede the functionalities provided by the
legacy commands.