SharpCap Forums

Could someone please advise as to how I can utilise the information contained in my Sharpcap Sensor Analysis for my Altair Astro 294c to evaluate the best gain to use? Also, I repeatedly hear unity gain, from this analysis how would I tell what that was please? Thank you

Once sensor analysis is complete the information is used by the "brain" in SharpCap's Smart Histogram. Here's a link to the relevant info in the User Manual. https://docs.sharpcap.co.uk/3.2/#Smart%20Histogram

TLDR: Once the SC has sensor data it can measure your sky brightness and recommend exposure and gain settings based on total observing time and weather your aim is unity gain or highest dynamic range.

Unity gain basically means input equals output, in other words in CMOS cameras no amplification of the signal. One photon in one photon measured.
Your camera manufacturer should list the camera's unity gain setting.

Couldn't find a unity gain listing on Altair Site but the ZWO version of this camera unity gain is 120. This may mean nothing for your camera since they gain scale maybe different. There are several Altair users on this forum hopefully one will provide the information.

The above is how I understand it, i'm sure corrections will be in coming if I have anything wrong. hehehe.

looking at the chart 1 e/adu is unity and would be between 400 and 562 on the snapshot you posted.

Cheers
Nick

Hi,

For this particular model of camera you can see that there is a very big drop in the read noise between gain 800 and gain 900. Because of this it's often worth using these cameras with the gain value to set to 900 to take advantage of the much lower read noise. For an accurate suggestion on what gain and exposure to use, do use the smart histogram/brain function which will perform the full calculations for you based on the information it has detected for your camera and your local sky pollution levels. Details of that are all in the manual.

Cheers, Robin

Thanks Guys for your replies.
I will do a smart histogram assessment the next time I get out and see what it suggests