M31 - Astrofest

[Garbz]

This was one of my goals for Astrofest. I can see M31 from Brisbane but I look straight through light pollution up north so my last multiple hour attempt barely produced anything other than a small glow in the core.

About 3.5 hours of data with 8min subs taken on a D800. Unfortunately there had to be one cursed problem for me at astrofest and that's my 3.5 hours were taken at f/2.8 and my 80-200mm lens has horrendous coma not to mention chromatic aberration. Oh and my exposures were a tad long so the core is blown out too.

Anyway still a much better picture than my attempts from Brisbane.

[RB]

Well done Chris !
I love M31 shots.

:thumbsup:

[peter_4059]

You are making pretty quick progress Chris - It takes a lot of people years to get an image they are happy with. This image has some great detail and colour.

Well done.

[RickS]

Nice result, Chris!

[h0ughy]

great shot Chris - love it. try PI's HDR multiscale for core details?

[Larryp]

Very nice, Chris :thumbsup:

[astronobob]

Really nice result Chris, gotta be happy with that :thumbsup: dig the subtle blue tinge about it too, splendid ! !

[dutch2]

Great shot. I love M31 shots.
:thumbsup:

[acropolite]

Love the colour and detail, I'd be very happy with that.

[naskies]

Looks nice, Chris :thumbsup:

Interestingly, I've noticed that a couple of my SLR lenses have noticeably worse coma in one corner (not noticeable at all for terrestrial shots). I wonder if it's related to mount misalignment or a lens collimation issue?

[Spookyer]

Cool. Do you mind sharing ISO you used?

Cheers
brett

[Garbz]

Thanks all for the kind words. I think having a history in photography and image processing has really helped dive into this hobby getting a lot out of the data.



Actually not, HDR Multiscale Transform for me has been an epic fail every time. I actually discovered a new tool this weekend that I am extremely happy with. Local Histogram Equalisation. I applied it to only the bright core in this image but also in my Corona Australis close up I used it to pull some wonderful detail out of the backlit dust around NGC6726/7.



My lenses appear to have the sharpest point centred quite well. However I had a Sigma 10-20 where the sharpness centre was noticably off to one side. Check it out: http://www2.garbz.com/DSC_7027.jpg Compare the centre left of the image to the centre right. I sent this lens back to Sigma and they advised that one of the elements was internally askew and repaired.

A lens used on the camera should be pretty plum. The mounts on lenses are usually machined quite well.



Certainly ISO640. I may have pulled this value from where the sun don't shine on the night, I didn't really have any method behind why I chose ISO640.