My first true experience with DSO astrophotography

72 days since my CEM25P has arrived, and I got just 1 day with open skies. Guess when the skies were open? Yes, in a night with a bright 97% illuminated moon.

Well, f… it! I needed to try some long exposures. And so I did.

For the first time ever I mount my CEM25P with my small 4″ Mak, a ZWO 60/280 guidescope and the QHY5L-ii attached to it. After struggling for about 5 or 10 minutes with PHD2, my telescope was working fine with autoguide. The skies were bad, really bad. The seeing was about 1″ for most time, but for several moments it went as bad as 2″.

Well, my first target was 47 Tucanae (NGC 104), a big globular cluster seen only from the southern hemisphere. It is my favorite globular cluster. Although Omega Centauri be the bigger one, 47 Tuc have stars of many colors and a denser core, which make the post editiong work more hard to do.

I began with the exposures just to see how bad the result would be, but for my surprise the stars appeared as a round dot! So round as possible with a 1300mm focal length telescope and a almost 2″ seeing sky.

I shot just 5 exposures with 2 min each, because M42 was getting higher in the sky and, man… what kind of a beginner I am if I not try M42, right?

Well, this is the final result (Until now) of 47 Tucanae, my favorite and loved globular cluster:


  • 5 x 120s ISO 640

Well, although it is a lame result, I’m happy. This is my official first DSO photography with my new CEM25P properly mounted, and I can’t forget the moon, which almost ruined the sky.

Right after that, I pointed to M42. It was just 30º high in the sky, but I was too excited not to try.

First I shot 10 frames of 2 minutes each. Then I tried 1 frame of 3 minutes. Round stars… and then another frame, of 4 minutes. Round stars again! Sadly, the clouds became when I was shoting a 5 minutes frame, and… good bye clear skies.

Maybe I pushed too hard on processing it…

M42 with a small maksutov
Foto guardada – com configuracoes defenidas.


  • 10 x 120s ISO 640
  • 1 x 180s ISO 1250
  • 1 x 240s ISO 640

Look at the trapezium:

I can’t wait for more clear skies and put my 135mm lens to the test!

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