Genie Nano-CL Series™ Operational Reference • 41Offset/Gain Control Details (On-Semi Python sensors)The Gain and Black level functions are applied at the sensor and/or on the digital image valuesoutput by the sensor, as described below.• Gain Selector = Sensor Analog: The gain function is a linear multiplier control in 0.01 stepswithin the sensor hardware.• Gain Selector = Sensor Digital: The gain function is a linear multiplier control in 0.1 stepswithin the sensor hardware.• Important: Digital noise increases linearly and quickly with higher gain values. Users shouldevaluate image quality with added gain.• Gain (Raw): Shows the raw sensor control for each gain stage or an alternative method tocontrol sensor gain.• Black Level: This offset variable exists within the sensor. The On-Semi sensors allow an offsetrange between 0 and 255 DN. The factory settings default value for each sensor used byvarious Nano models, is recommended as per the sensor manufacturer design specifications.Note: With the factory default offset, testing a camera’s black output in 8-bit mode may showa 2 DN value difference across the image. Changing the Black Level value up or down will pushsensor noise (present at the sensors native bits per pixel) to fall within one 8-bit value, thus thenoise becomes hidden.On-Semi Python Sensors Gain Stage DiagramAnalog Gain Control Post Digital Gain ControlOn-Semi Sensor Gain StagesAnalogBlack LevelControlDigitalDigitalDigital Gain ControlOnSemi Sensor Artifacts with Fast Readout ModeApplicable only when Flat Field Correction is purposely disabled.When Fast Readout mode is active (cameras with OnSemi sensors), the row blanking and rowreadout occurs in parallel in the sensor. This reduces the total frame readout time resulting in afaster maximum frame rate. As a consequence of this mode there are minor column artifacts (ofvery low DN), typically of no significance and irrelevant for many imaging systems. Note that thesecolumn artifacts will become more prominent as sensor gain is increased.
