Seby

Thank you for your tips, vlaiv, it's an interesting idea. I never tried with mosaics but I think that the tecnique that you describe with shorter times for the single panels is very interesting and the advantage is that I could use the f/4 telescope that I already have. I have to try this with some easy nebula once the lockdown period is finished.

Thank you for all your replies, now I have understood better! Yes, rl, I love my simple f/4 Newton telescope 🙂 but for some large nebulas a shorter focal lenght would be better so I am thinking to buy also a short focal refractor at some point or, maybe, a long focal photo lens.

Hi, I have a question about refractor telescopes used together with monochrome cameras. I've read that the benefit of apo and semiapo refractors is that they reduce the chromatic aberration. It's of course very important for visual observations and color cameras but does it make difference to use an achromatic or apochromatic telescope for imaging with a monochrome camera and color filters or narrow band filters? Are there also other advantages in apos beside the reduced chromatic aberration? Thank you for your help!

Hello, I'm Sebastiano and I live in Sicily (Italy). First of all sorry for my errors in English but of course it's not my mother tongue 🙂 I have often read astronomy posts on the forum during the last years and now (unfortunately) due to the lockdown in Italy I've more time for my hobbies and also to register to the forum. My interest in astronomy started in the nineties when I was about 15 years old. Back in that years I observed a lot with my 4" newton telescope. I liked to draw everything from star clusters to sun spots (but I'm terrible at drawing). I also tryed a little astrophotography with my father's Nikon F. I had not great results but it was just in time the try astrophotography before the digital revolution. After many years of break I returned to the astronomy hobby in the last 10 years with special interest for astrophotography. At present I have a GSO 8" f/4 Newton telescope and take pictures with my Canon 70D. Unfortunately a lot from my balcony (Bortle 8 town center) or sometimes from the surroundings at the observation area of our local stargazer club.