April 2021

M101

  • Nik 

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.


200PDS + Hypercam + HEQ5. 300s x 14, 180s x 60, approx 4 hrs total exposure

Rosette Nebula

  • Nik 

Way back on the 3rd February I had a go at imaging the Rosette Nebula and I’ve finally gotten round to processing the data.

ES ED80APO, HEQ5 - Guided. 600s x 12 / 300s x 12 / 60s x 19 subs. Total exp. 3 1/3 hrs

29/30/31st March 2021

  • Nik 

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.
Skywatcher 200PDS, HEQ5 - Guided. 600x 42 / 300 x 50 / 180 x 20 subs. Total exp. 12 2/3 hrs

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:

  1. MultiscaleLinearTransform to do some noise reduction
  2. Stretch
  3. MultiscaleMeridianTransform to reduce the blotchy background
  4. HistogramTransform to reset the blackpoint
  5. 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.

Skywatcher 200PDS, HEQ5 - Guided. 600x 34 / 300 x 34 / 180 x 20 subs. Total exp. 9 1/2 hrs (Selected data)

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.