Testing the Sharpstar 76EDPH with the ASI183MM

It has been cloudy for the last months, this February New Moon was totally clouded out! With exception of lastThursday, February 20th: after an active rain zone passed through – with heavy wind and hail – the night sky cleared out.

After midnight till 4 am a clearance allowed me to test the setup. The test subject was the dwarf galaxy Leo 1 next to the bright Regulus.

Regulus en Leo1 3x5x120s RGB ASI183MM Sharpstar76 G111

This image was a quick test. Not only for the optics/camera combination, but also for the automation. SGP was used to automate, autofocus, and Solve& Sync. Where before I could not match the Solve coördinates from SGP back into Cartes du Ciel, this time it worked. The secret was to run both applications as an administrator. So both will connect to the EQMOD hub. Syncing in CdC (Manually) will update the EQMOD coördinates, hence also the SGP co*ordinates. And it works in both directions: Solve & Sync in SGP will update CdC. This is great!

I still had Luminance images also, but I did not add these: it were fuzzy frames and some reflections appeared. I suspect this Luminance filter is not ok.

Attempt to mosaic

After creating the Heart nebula in a mosaic a month ago, we had some semi-clear nights last week, in which I could try and stitch the Soul nebula to the Heart.

Unfortunbately these nights were also very foggy, sometimes fog banks floated over, with barely star visibility. The good news is that SGP (Sequence Generator Pro) kept up trying, despite star loss in PHD, to continue making lights. While sleeping. So that’s really wonderfull.

The end result, needless to say, did have that much gradient sin the final image that I do not consider it a result. It’s more an exercise. The final mosaic had 10.000×12.000 pixels and took 1,5 Gb TIFF or FITS size. Both AstroPixelProcessor and Photoshop had issues digesting this large file. In fact it’s so large that Astrobin or this website cannot upload it.

10% of a 11.000×12/000 pixel mosaic 6-panel.
A 2-panel (part of ) the Soul nebula. It’s clear by the halo’s around the brighter stars how foggy it exactly was.

This is a two-panel mosaic each panel of about 10 300-seconds 800ISO frames with the 120mm Esprit F5,5 and Nikon D750
. The remaining panels on the left of the “foetus” were fogged out.

Heart in the Sky

The Heart Nebula in Perseus is an interesting region of red hydrogen clouds mixed with dark nebulosity and bright star clusters. This was a test-run: first light with the Sequence generator Pro combined with the Nikon D750 (with autofocus by PegasusAstro, worked wonderfull). Second test (living dangerously!): first attempt to mosaic automatically with SGP.

The D750 would crash SGP when hitting the “link” button: as soon as I touched that button, SGP would collapse and simply vanish in thin air. Solution: install the 2013 C++ redistributables.

The Optolong Pro filter OR the reducer/flattener (or the combination) imho added a lot of vignetting and uneven illumination to the image, which I had a hard time eliminating. So next test would be with a regular Nikon T-ring. If that does not solve the issue then it must be the F5 reducer. I noticed earlier already that images at F7 with the Nikon were a lot cleaner.


IC1805 or the Heart Nebula in Perseus. Image dedicated to my mom who passed way in September age 79.