Quote:
Originally Posted by Peter Ward
I have one and the quad corrector.
Every AP scope I have owned has run out of light
when pushed to extreme magnifications, as opposed to lesser instruments which invariably show aberrations in one form or another.
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Peter I agree they’re very very good - but they’re not alone. Frankly these run out of puff at 260X (X2 per mm of aperture). But you can’t beat the physics of limited aperture vs diffraction.
The snag is, would you drop north of $10k on a 130mm scope vs other choices at that price ? My 9” Santel cost half as much as these scopes and it likewise runs out of light before you see any aberrations. And it totally slays these small refractors - 440X is fine if seeing permits.
Likewise anyone with a Questar 7 would not sniff at this, nor the buyer of the SW 180 mak I sold recently.
Similar a well made Dob with a good mirror - say a Zambito or Royce - is a far better instrument.
Aperture and long focal length rule if you want serious magnification. There’s nothing better than a really long FL reflector or cat with small obstruction. Zero, if you are prepared for a schiefspiegler at f/23.