Mars with 200PDS 2/9/2020

[AbsolutelyN]

This is my first attempt at Mars in about 5 years, taken at about 3am this morning with 200PDS, 3x barlow and ZWO 224MC. 
It's stacked with AutoStakkert!3 and then I've sharpened it up in PixInsight. Does anyone have any ideas on removing (or what causes) the white arc by the polar cap? Tried a few de-ringing options but always lost too much detail when trying to remove it. Any thoughts much appreciated.
 

Third attempt merged with a de-ringed version to try to remove the white arc.

Second attempt with better colour balance:


Processed with Registax wavelets + touched up in Photoshop (removed atmospheric dispersion)

Original stack and simulated comparison

 

Edited September 2, 2020 by AbsolutelyN

[morimarty]

I really like the colour balance definitely to my taste. You have also captured some nice surface detail too. The 8inch PDS is a great all round scope.

[AbsolutelyN]

2 hours ago, morimarty said:

I really like the colour balance definitely to my taste. You have also captured some nice surface detail too. The 8inch PDS is a great all round scope.

Thanks, it's amazing what you can get with such a modest scope, quite pleased for first attempt in years. Bit of a learning curve to process though. 

[CraigT82]

Really nice work, tons of readily identifiable features to be seen there. The edge rind effect is due to diffraction apparently and is tough to deal with but you've doen a good job withe the third attempt there 

[AbsolutelyN]

7 minutes ago, CraigT82 said:

Really nice work, tons of readily identifiable features to be seen there. The edge rind effect is due to diffraction apparently and is tough to deal with but you've doen a good job withe the third attempt there 

Thanks - I would have never guessed it was diffraction. I assumed it was some kind of stacking artefact or from the wavelets. Do you know if atmospheric artefacts like this can be avoided with mono camera RGB filters?  

[CraigT82]

42 minutes ago, AbsolutelyN said:

Thanks - I would have never guessed it was diffraction. I assumed it was some kind of stacking artefact or from the wavelets. Do you know if atmospheric artefacts like this can be avoided with mono camera RGB filters?  

Some good info here from Martin Lewis...

https://skyinspector.co.uk/mars-edge-artefact/

Note that there will be an article on this effect in next months BAA journal (if you're a member) but I assume it will be added to Martin's website afterwards too. 

[AbsolutelyN]

14 minutes ago, CraigT82 said:

Some good info here from Martin Lewis...

https://skyinspector.co.uk/mars-edge-artefact/

Note that there will be an article on this effect in next months BAA journal (if you're a member) but I assume it will be added to Martin's website afterwards too. 

That's an excellent article, many thanks for the link