M33 Triangulum Galaxy - First light using IDAS D2

[bdlbug]

So, highly motivated by @peter shah and his post earlier  this week of M33 - which was breathtaking, I captured around 4.5 hrs of RGBHa subs this week (Tues/Wed) under less than ideal conditions as although there was no moon the transparency of the sky was quite poor. This was also my first image since fitting an IDAS - D2 filter into my optical train, it is positioned behind the reducer but in front of the filter wheel so all the light is pre-filtered through the D2.  It does seem to improve my sub quality - I have the usual variety of light pollution around me, from the town streetlighting, playing field floodlights and logistic centers, but my RGB channels once processed though APP were much cleaner and I did not need to use Astro Flat pro as much, within PS. There is a issue with top right of the image but I think that is a flats problem from the Ha subs.

So captured with AT106EDT with 0.75x reducer/flattener and my ASi1600, The RGB subs were 120s Ha Subs 180s all at unity gain, 139/21 - did not capture luminance as sky conditions were not very good. Captured with APT processed with APP and PS CC. I previously was using 60s for RGB subs, so managed to double exposure without getting obliterated by light pollution.

I have not imaged this target before so I was unsure of the colour balance that I got as the galaxy is very blue, but I have the background in a (Photoshop balance  22, 21, 20  with some variance over the image) and the stars don't seem to be badly  'wrong' - anyway happy if anyone can say if this is a reasonable colour balance for this target.

 This is also full frame, only slight crop to remove stacking overlaps.

thanks for looking and advice/comments appreciated

Bryan

[bdlbug]

I re-worked this image this evening, using the calibration tools in Astro Pixel processor for background and star colour and this processing gave a different result from the same data set, there is definately more red/pink in this version - not sure where to go with this now.......

[Adam J]

8 hours ago, BDL_Bug said:

I re-worked this image this evening, using the calibration tools in Astro Pixel processor for background and star colour and this processing gave a different result from the same data set, there is definately more red/pink in this version - not sure where to go with this now.......

this looks more like the color I got when I shot this.

[bdlbug]

Thanks Adam - thought it looked better but when you are in front of screen for hours it helps to have a informed second opinion- I’ll see if I can reprocess and reduce the noise as the APP version was a bit of a smash and grab process

Bryan

[peter shah]

On 13/10/2018 at 09:01, Adam J said:

this looks more like the color I got when I shot this.

That's a wonderful shot Bryan, I don't know about you but I found the outer arms and quite the challenge. You have some real fine detail coming through in this shot, I really like your last rendition. Lovely work.

[bdlbug]

Thank you Peter - really appreciate your comments, regards the outer arms, yes trying to push the image to get some detail there without creating a mess of noise and control the remainder of the galaxy and also try to preserve the star colour - all bring their own processing challenge - particularly with this image I watched more advanced processing tutorials and used different (new to me) masking and layers techniques to help highlight detail but not obliterate the image with noise. I also applied a PS plugin called ClariSky, https://photographingspace.com/product/clarisky/  -It is sold for enhancing milkyway images , but it does bring something to dust-lanes in galaxy processing. My biggest challenge was my red channel as it was significantly 'softer' than the blue and Green, This is extract from the APP report in order, Blue, Green, Red

Think this was probably due to the high cloud during my imaging time, as I have found the Baader filters to be very parafocal so not requiring refocus when I change filter.

Hopefully can revisit this target with more transparent skies before it goes too far west and is 'lost' in the light pollution bubble of logistics warehouses.

 

thanks Bryan