SharpCap Forums

After doing the previous sensor analysis on the ASI178MC, I tried stacking with 3.2 using a low gain value. The problem is that no matter what I tried, I couldn't get the stacking to detect any stars. I am only able to stack one I get the gain around 300+.

As note, due to my current setup, I cannot use real large exposures, so I am usually doing 4-5s max exposures. This worked ok with high gain but there was too much noise, so I was hoping to use a lower gain instead.

With 4.0, I am able to stack a bit more but it seems to detect hot pixels as stars which causes other problems.

Any suggestion would greatly appreciated.

Hi,

if you are not changing the exposure length then actually the amount of noise (relative to the amount of image signal) remains basically the same as you change the gain. All that happens when you turn down the gain is that both the noise and the image become fainter until you get to the point that the noise is hard to see (but it's still there). So, my first advice would be to stick with the gain level that works The noise will gradually fade away as you let more frames accumulate in the stack.

I would be interesting is seeing a few of the individual frames that you are having trouble stacking in 4.0 - that would let me investigate if there is anything I can do to help reduce the effect of hot pixels.

thanks,

Robin

Thanks Robin the reply. I will go out tonight and capture some more to see how things work in 4.0.

Is there a way to have the rawframes be saved in FITS instead of PNG?

Hi,

yes, just set the preferred still file format to FITS in the settings - see https://docs.sharpcap.co.uk/4.0/#Saving%20Options

cheers,

Robin