Thanks for that Peter. I

[Mr Robert Jonathan Marshall]

Thanks for that Peter. I particularly found the CA value interesting and very helpful. A really good point about the use of filters re CA, but at the end of the day I feel it’s a bit of a bodge. Funny that you should mention a short tube SCT or Mak, as the chap at my nearest Telescope dealer suggested that too. However, I don’t feel a long focus refractor would be too awkward and difficult on my stairs, well not at the moment anyway. That of course could change! The other thing that really puts me off re a SCT or Mak is the relatively large central obstruction, that as you know, crucifies diffraction limited objects. Two questions I’d like to ask you though. To the best of your knowledge, do Bresser’s and Skywatchers originate from the same factory? in China obviously! Also, and I feel slightly embarrassed to have to ask you this, but can you clarify an abbreviation you use more than once, and that’s ‘OTA’. It’s obviously Off The something or other! 🙂
Like the big Newtonian behind you! 🙂