I have been trying to expand my understanding the concept of Gain. My imaging camera is the Altair Astro 26C.
In SharpCap, it appears the defulat Gain is 100. I have the following questions:
I have attempted to set the Gain lower than 100, but any attempts always reverts back to the default value of 100.
1) Can a user set the Gain lower than the default of 100?
2) If the default Gain cannot be set lower, Does the default of 100 represent a Gain of true Zero (no Gain) or an actual gain of 100?
3) For the AA26C- is there a place where I can locate the recommended offset?
4) I am unable to locate the offset function in SharpCap- where is this located?
5) I can't find any documentation on the FLIP function. Is it related to Meridian Flip? What is this function use for?
Kind regards,
Brian
SharpCap Gain
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Re: SharpCap Gain
Hi Brian,
the gain values on Altair cameras (and also some other brands) work differently to the ones on ZWO/SVBony/etc.
Altair gains start at 100, which is the lowest possible gain for the camera. Gain 200 is twice as bright as 100, 400 is four times as bright and so on. It's actually quite logical and easy to understand once you know what is going on. For comparison, ZWO gain starts at zero, and going up by 60 doubles the brightness, so 60 is 2x as bright as minimum, 120 is 4x as bright, 180 is 8x and so on.
In terms of offset, the adjustment is termed 'black level' for the Altair cameras. The recommended value depends on the gain you are using - it's simple to find by setting the gain and exposure that you intend to use, taking some dark frames with the histogram showing and adjusting the black level control until the histogram peak is separated from the left hand side of the graph. Higher gains will require higher black level values.
The flip function mirrors the image in either the vertical or horizontal directions, or both. However for Altair cameras it is only available in RGB mode, so is not recommended for astronomical use. It's more useful to get the image the right way round if you are using the camera for other sorts of imaging.
cheers,
Robin
the gain values on Altair cameras (and also some other brands) work differently to the ones on ZWO/SVBony/etc.
Altair gains start at 100, which is the lowest possible gain for the camera. Gain 200 is twice as bright as 100, 400 is four times as bright and so on. It's actually quite logical and easy to understand once you know what is going on. For comparison, ZWO gain starts at zero, and going up by 60 doubles the brightness, so 60 is 2x as bright as minimum, 120 is 4x as bright, 180 is 8x and so on.
In terms of offset, the adjustment is termed 'black level' for the Altair cameras. The recommended value depends on the gain you are using - it's simple to find by setting the gain and exposure that you intend to use, taking some dark frames with the histogram showing and adjusting the black level control until the histogram peak is separated from the left hand side of the graph. Higher gains will require higher black level values.
The flip function mirrors the image in either the vertical or horizontal directions, or both. However for Altair cameras it is only available in RGB mode, so is not recommended for astronomical use. It's more useful to get the image the right way round if you are using the camera for other sorts of imaging.
cheers,
Robin
Re: SharpCap Gain
Thank you Robin- this information really helped me to better understand my Altair equipment and SharpCap functions.
Kind regards,
Brian
Kind regards,
Brian