Opticallimits

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This is only a "work in progress" as I'm still getting more image data while I write this. Tonight was the first clear night in a while. I might not have many chances and am making the most of it.

 

Equipment:

Canon 7D mk2

Astronomik CLS CCD filter (EOS-clip)

Sigma 150mm f/2.8 macro

Skywatcher EQ6 mount

 

The mount is set to track the background stars. I'm not sure how much the comet will move relative to that during this imaging session so that will be interesting during further processing. I've taken just over an hour of data so far, but about 1/3 had to be rejected due to cloud. The sample presented so far used 19 of 30 second exposure. I left the lens wide open at f/2.8 and chose ISO1600 as a balance between image brightness and headroom. Even with the light pollution filter in place, the remaining background level is a bigger limiting factor than the sensor noise. I hope to get at least an hour of cloud-free exposures before doing another process. It is very CPU intensive so I don't expect to complete that tonight.

 

Software wise I'm using PixInsight to do the heavy lifting, and usually finish off the cosmetics in Photoshop Elements.

Hi Popo,

 

   Looks like very good work in progress!

   I did a product search on your Skywatcher EQ6 mount, Hey, nice piece of gear!  then watched a video showing the mount and the rest of the range of their telescopes and other products, They also showed their fused mirror blank before it had been ground , seriously impressive stuff from a very impressive company. Nice!

 

  I hope you get the clear skies you need and looking forward to your posting updates.

I haven't really looked too closely at the rest of their products. The EQ6 mount was chosen as it was generally regarded as the best value one with a decent performance. There are few clear nights in winter for me to do much of this nowadays, so I've largely stopped other than for more transient events like comets.

 

In the end I took a total of 161 usable exposures (many eliminated due to cloud) and they're still processing now. The temporary files just passed 100GB...

Updated process with approximately 80 minutes of exposure now. Tail is clearly visible but I'm still finding it hard to process around the noise.