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ZEISS DTI thermal imaging cameras. For more discoveries at night, and during the day.

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  1. Musoman

    Example with a 90mm Maksutov-Cassegrain type scope

    From my limited knowledge, the mirrors are fixed, unlike Maks which move ( or at least the secondary mirror moves ) and can introduce mirror flop when focusing, which causes image shift. I dont know how much of a problem this is with quality Maks and Schmidts though. In reviews i read, the...
  2. Musoman

    Example with a 90mm Maksutov-Cassegrain type scope

    Apparently the RC scopes are better than MaK Cas or Schmidt Cass for photography...so i read anyways As for weight, some serious guys lug around Canon L 600mm f4's and Sigma 800mm f5.6s ...somehow they cope, as the Canon is a tad under 12Lbs and the siggy is tad under 13Lbs , so on a par with...
  3. Musoman

    Example with a 90mm Maksutov-Cassegrain type scope

    Entirely possible it would yes, but i havent a clue as this area is right out of my comfort zone
  4. Musoman

    Example with a 90mm Maksutov-Cassegrain type scope

    The FL wouldnt be a problem with a .66 or .75 reducer, but the weight is
  5. Musoman

    Example with a 90mm Maksutov-Cassegrain type scope

    I think it would be too heavy ( i couldnt find info on the weight depsite a lot of searching ) - its quite long too at 20" although shorter than my SW120 The design of RC's seems to be far better than Mak or Schmidt for CA correction, + there's zero mirror flop
  6. Musoman

    Example with a 90mm Maksutov-Cassegrain type scope

    I see - thanks Phil In which case, i'm wondering if the modern Celestron C5 has sorted out that sort of focusing problem, because in my searchings, the C5 is the only Scope i have any interest in. Its also been given the XLT coating that old version never had. Maybe I'll try one out in the...
  7. Musoman

    Example with a 90mm Maksutov-Cassegrain type scope

    Cheers Paul - straight forward info
  8. Musoman

    Example with a 90mm Maksutov-Cassegrain type scope

    Thanks Blue - by the way, does the Mak Cass focus in a similar way to a refractor ? EG... 2 wheels either side of the focus tube for easy right or left handed people
  9. Musoman

    Example with a 90mm Maksutov-Cassegrain type scope

    Is it the case with Mak-Cass , Schmidt-Cass or whatever , that if you attach a DSLR ( not a compact / fixed lens ) directly to the scope without DSLR lens or Scope Eyepiece or Prism, that subjects will be upside and back to front ? This is something I like about refractors, in that direct...
  10. Musoman

    Example with a 90mm Maksutov-Cassegrain type scope

    Thanks for that Jason Its just occurred to me that a reducer is not the same as a field flatener, but maybe you can get a reducer / flatener in one piece ?
  11. Musoman

    Example with a 90mm Maksutov-Cassegrain type scope

    Cheers Paul ... this is all curiosity only, as i havent even given the SW 600 f5 a decent workout yet. Got that DOI 1.5x TC to try yet - even got it in Pentax mount . Lucky or what
  12. Musoman

    Example with a 90mm Maksutov-Cassegrain type scope

    Jason, i noticed on the Intes website that the Alter M500 can be fitted with an optional focal reducer of 0.55x which brings the f10 ratio to f5.5, but i assume this will also reduce the focal length too, from 1270mm to around 700mm ( 1270 x 0.55 ) Is that how focal reducers work ? Can any...
  13. Musoman

    Example with a 90mm Maksutov-Cassegrain type scope

    Cheers for that link to the Orion Al. I think f12 would be just too narrow an aperture for me. The 1500mm+ focal length is huge, and maybe hard to control...what do you think ? Mind you, i know you can fit some kind of focal reducer to get the aperture down to f6 or f7 ( thats a guess )
  14. Musoman

    Example with a 90mm Maksutov-Cassegrain type scope

    Found someones review of the Intes Alter M500 against the Orion 80 ED which is the same as the SW 80 ED i believe http://www.astromart.com/articles/article.asp?article_id=433
  15. Musoman

    Example with a 90mm Maksutov-Cassegrain type scope

    :smoke: I have little money anymore to experiment Al, so not yet. Its very interesting to read about the Mak Cass scopes though. Maybe in the future, but it seems the quality Mak Cass scopes are not cheap. I looked at the Intes Micro russian models and the smallest Alter M500 ( 127mm / f10 /...
  16. Musoman

    Example with a 90mm Maksutov-Cassegrain type scope

    More informative posts Jason - cheers. So how did you personally find trying to shoot birds with such high apertures like f10, f12 etc. Did you only take your scope out on sunny days and avoid late afternoon / evening low light scenarios ?
  17. Musoman

    Example with a 90mm Maksutov-Cassegrain type scope

    Yep they are impressive - thank heavens for birds that sit still ;) So, regarding diameters, can i assume the apertures get worse as the diameter gets larger ? EG .. 90mm Mak Cass would have wider aperture than 130mm Mak Cass. In which case, for those interesetd in trying out these scopes...
  18. Musoman

    Example with a 90mm Maksutov-Cassegrain type scope

    Informative post Jason. One thing that puts me off is the aperture of the Mak Cass being very poor, ( f13 ? ) even if the IQ is ahead of DSLR mirror lenses. Wouldnt a Mak Cass be usable in only the best of light conditions / bright sun day etc ?
  19. Musoman

    Example with a 90mm Maksutov-Cassegrain type scope

    Thanks Phil
  20. Musoman

    Example with a 90mm Maksutov-Cassegrain type scope

    Thanks Rick Would a Mak Newt be comparable to a Mak Cass ?
  21. Musoman

    Example with a 90mm Maksutov-Cassegrain type scope

    Just wondering, can you get Mak Cass scopes with a better ( wider ) max aperture than F13.8 ? Also, what type of glass are they .. ED, FPL53 etc ? Just thinking about the problems of CA with poor quailty glass. I dont know a thing about Mak Cass scopes, so i might be asking the wrong thing
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