SharpCap sensor analysis

[Galileo]

Has anyone done tried this ?

 

This is my result from a RisingCam IMX571 colour camera so it's the same sensor as an ASI2600 and has similar graphs.

 

Now I've done it I don't really know how to interpret the result or use it. Am I right in concluding from the graph that unity gain is not possible? 

 

 

[GazAstro]

The learned (but argumentative) gents on cloudy nights suggest the the 2600 doesn't have a unity gain.

They recommend 0 gain for broadband and 100 gain for narrowband.

https://www.cloudynights.com/topic/777602-gain-and-offset-values-for-asi2600mm/

[Galileo]

Thanks Gaz I'll give that a read later. 

 

Does the histogram during capture not influence your gain setting? Surely your histogram would be waaaaay over the the left on 0 gain?

 

I thought setting the gain to achieve a 1/3 histogram was the way to go. I certainly did that in my DSLR days.  

[paul]

On 5/25/2022 at 2:16 PM, Galileo said:

Thanks Gaz I'll give that a read later. 

 

Does the histogram during capture not influence your gain setting? Surely your histogram would be waaaaay over the the left on 0 gain?

 

I thought setting the gain to achieve a 1/3 histogram was the way to go. I certainly did that in my DSLR days.  

If read out noise is very low and thermal noise also low - as it is with a cooled CMOS astro camera you can ignore that guideline and stream line your process around fixed shorter exposures and lower gain settings. That way you are less likely to blow out bright stars. 

 

If you have the computer processing power then 100 x 60 second images will tend to give you a better result than 10 x 600 second images just because guiding errors accumulate and tend to blur the target and a higher percentage of shots will be ruined by gusts of wind and satellite trails. Personally 120 seconds is a long as I go for (for narrow band) for minimal burn out, I could probably go longer now my guiding is under control.