Electronic gain and IC capture gain

[lorenzo_V]

Hi I have a question concerning gain settings in IC capture.
Is there a a general rule to know the value of the electronic gain (in dB) from the gain
parameter setted from Device properties in IC Capture?
Thanks
Lorenzo

[Michael Kirmse]

Hello lorenzo_V,

the ratio of the shown gain value to the electronic gain value in dB varies with the type of camera. What cameras do you use?

[Stefan Geissler]

Lorenzo,

most of our CCD cameras have the gain starting at 0 ending a 36 db. The gain rises linear with the value set.

[lorenzo_V]

Michael,
I use a DMK21BF04 electronic gain (0-36 dB) gain value 260-1023.
So if the relation is linear between the dB and the gain value I've to multiply the value for the ratio 36/764 to obtain the gain in dB.
Is it correct?
Best regards
Lorenzo

[Stefan Geissler]

Yes, I think so. Please see the attached image

[lorenzo_V]

Stefan,
I'm a little bit confused having a look at the graph. I think that @ 0 dB the abscissa (register value) has to be 260, doesn't it?
Best regards
Lorenzo

[Stefan Geissler]

Lorenzo,

what you see is an excerpt of the documentation of the camera engineers. A little gain must be a minimum setting, which is 260, in order to see an image at all. Therefore, the minimum value is 260, which seems to be 8db in the camera electronics.