GAIN is the pre-ADC programmable gain amplifier setting. OFFSET is the ADC voltage offset setting. The correct setting of OFFSET and GAIN can change the CCD's system gain,to make the CCD output signal range match the ADC quantization range, so as to get the best dynamic range.
Suitable for most of the GAIN and OFFSET Settings:
1.Set the gain=0,set the exposure time to 0,cover the lens ,then shoot a BIAS frame.
2.Watch the local average value of the captured images(you can use the Noise Analyze function of EZCAP,image process->noise analyze).The ideal average value is around 500 to 3000.If the value is higher ,then you should reduce the OFFSET.If the value is lower ,then you should increase the OFFSET.Repeat steps 1-2 to obtain the ideal OFFSET value.
3.Open the lens cover,increase the exposure time ,then use the uniform light source to take a saturated exposure image.Watch the local average value of the captured images.If the value is less then 60000,you should increase the value of GAIN.If the value is 65535 ,you should reduce the value of GAIN. Repeat this step to obtain the appropriate GAIN value.
4.Under this GAIN value ,repeat steps 1-2 to obtain more accurate OFFSET value.
Note:For some QHYCCD products when you use bin modes of 2*2,3*3,4*4,images may reach 65535 even the gain is 0,so you just set the gain to 0.