A nice clear, dark, moonless (well until about 4-30am) night last night. Came as bit of a surprise since I hadn’t been keeping an eye on the weather recently since we’ve been packing.
Setup seemed to go well, which in my experince is a sure sign that something else will go wrong later on. Sure enough I couldn’t get my guiding working decently, so I ended up being limited to 3 minute exposures.
I really wanted to have one last go at the cone nebular but it was far to low in the sky by the time I got everything working so I settled for M101. Seems to have come out quite well.
So three(ish) nights of fairly clear skies with fairly good seeing finally. Pity the moon was waxing but we can’t have everything.
So I had quite a loot of light for this shot of M81 and M82. Some of it was fairly light polluted though and there was some high cloud in some but I though I’d see what I could make of it by just dumping the whole lot into Astro Pixel Processor. I think it’s done a reasonable job but I did initially end up with a fairly blotchy background.
I used the APP light pollution tool on the complete stack and then used PixInsight to stretch and process it. My workflow looked something like:
MultiscaleLinearTransform to do some noise reduction
MultiscaleMeridianTransform to reduce the blotchy background
HistogramTransform to reset the blackpoint
HDRMultiscaleTransform to bring out some detail
I had quite a lot of trouble with step 5. The enhancement worked fine in the preview but went wired for the whole frame. In the end I made two previews of the galaxies, did the transform, saved both the images then merged them into the final image using GIMP.
I’m quite pleased with the first result but I was a bit bugged by the blotchy background so I went through the raw data by hand and filtered out the cloud polluted frames. This cut out about 3 hrs of light.
The background did indeed come out a lot better so step 3 wasn’t needed and step 5 worked on the whole frame but on the whole I like the first attempt better.