I’m really excited to share some progress on my astrophotography setup. For those of you who don’t remember, over 7 months ago I purchased a used “Costruzioni Ottiche Zen” Simak 240.

Unfortunately the specimen presented an acute pinching somewhere in the optical train, and despite several attempts, following the instructions of the manufacturer, the problem could not be fixed.

I’m not sure whether the seller swindled me or not, I don’t have any reason to doubt him, but hard facts are hard to belie.

After I’ve shipped the telescope back to the manufacturer, we will know if it’s something that might have happened during the original shipping.

For some reason better left untold, it took forever until I was able to make progress and get the Simak 240 off my mount, and replaced.

I now have a GSO RC8 that my good friend Samuel lended me (and I suppose I’ll just buy it from him), which is still not working as I would like.

However, last night I discovered that the tilt and/or decollimation issues are rather paltrier than I thought, and the bulk of the problem lied in a poor configuration of my guiding setup!

After tweaking my mount and MaximDL, I was able to finally get a star shape that is close to decent, albeit not quite there yet. I have a few things left to try, and then hopefully the thing will be collimated properly and I’ll just never touch it again, come what may.

Finally, did I ever forget to mention, there’s some small issue with internal reflections. You can see it in the image, and it belongs to a magnitude 5 star about 1 degree out of view.

It’s a stack of 3x900” + 17x600” on NGC 3628, quickly treated with PixInsight:

  • STF applied to HT
  • HWT 6x2 + 5x1
  • LHE
  • Deconvolution

With luck and determination, I should be able to improve the guiding further, and then I’ll be closer to a good setup.