Skywatcher Quattro CF f4/250 Newtonian astrograph with Moonlite 2inch hi res stepper focuser. $1500 reduced $1300.
This is a seriously good imaging scope. Star tests show that it is effectively diffraction limited and stray light is very well controlled by extensive internal baffles and a repaint with blackboard paint. The primary mirror mounting is well designed and strong and the large 80mm secondary illuminated my ASI1600 camera with only minor vignetting - should be fine up to around APSC sensor size. The mirrors were claimed to be Pyrex and the coatings are excellent (but see note below).
The carbon fiber tube is very stable and rigid, but it needed a little extra bracing at the focuser to keep in perfect collimation at all angles with my imaging train. I also moved the mirror up 10mm to get my RCC1 coma corrector out of the light cone.... but it will still work equally well with other quality coma correctors. The cork side supports on the main mirror were replaced with polythene so that the mirror slides freely into place at any angle. With the minor modifications, the scope maintains collimation for long periods – only needs an occasional tweak when something is changed (eg the camera dessicator is recharged or optics are cleaned).
It is fitted with a high quality 2 inch Moonlite high res stepper focuser – no controller for the Moonlite, but it is fully compatible with most of the digital controllers on the market. The Moonlite is very solid and was a positive upgrade to the scope.
The scope has one minor flaw. Early on, I found that it was possible for the draw tube of the original Skywatcher focuser to fall into the OTA – which it did. It damaged a very small spot of coating on the secondary, but thankfully did not reach the primary. On the basis of others' experience, I touched up the small spot with flat black paint and, since it did not affect the imaging performance in any measurable way, decided to leave as is.
10 inch f4 CF scope+
dew shield and tube rings (will need a bar to fit your mount)+
Moonlite 2" focuser+
Moonlite 2”/1.25” adapter
I don't have original packaging, so collect from Adelaide.
The original donut was not centred properly so it was removed. This home-made one is rougher looking, but has the advantage of being in the right place - and of course, the centre of the mirror is not used in image formation. This is my third Newtonian - they have all had slightly misplaced donuts. Cheers, Ray.
