GSO - 6 inch F6 Imaging Newtonian Telescope
GSO 6" F/6 Newtonian reflector telescope with 2" Crayford focuser, visually optimized. High-quality primary mirror with 94% enhanced reflectivity.
This Newtonian is a powerful all-round telescope for amateurs who already have a good astronomical mount with tripod.
High definition parabolical primary mirror, better than typical Chinese mirrors
94% enhanced reflection for a brighter image
Secondary with 45 mm minor axis for good illumination and little obstruction at the same time, glued on a metal holder
Focus position optimized for observing (focus approx. 50 mm above 2" receptacle)
Rigid steel tube instead of a wobbly aluminium tube
Ultra-smooth Crayford focuser for much smoother focusing motion and zero image shift.
Comes complete with tube rings, 6x30 finder, 2" focuser and reduction to 1.25"
What's in the Box
150mm f/6 Newtonian optical tube assembly
2" Crayford-style linear bearing focuser with 1.25" eyepiece adapter
8x50mm straight-through finder with bracket and base
Tube rings
8" Vixen-style dovetail rail
2" extension tube with 35mm extension
Front dust cover
No instruction manual is included for OTA
There are many Newtonians for Astro-Photography, but the GSO 6" F/6 is optimized for visual observation
Almost every Newtonian has a focus position which is optimized for astrophotography. The result is insufficient illumination through a secondary with too little diameter (or too much obstruction if the secondary mirror is too large) and an unnecessary long distance from focuser to focus, making an extension tube a necessity.
Together with GSO, TS has created a Newtonian which provides best results for the visual observer. The secondary mirror has 45 mm minor axis which results in very high contrast and sharpness for moon and planets. The image matches the typical one of an excellent 4.5" apochromatic refractor and at least the one of a very good 105 mm apochromat. The image is even brighter.
With a focus position approximately 50 mm above the 2" receptacle, almost any common eyepiece can easily be focused, the illumination allows even using 2" eyepiece with full brightness over the entire field. By the way: due to an aperture ratio of 1:6, Plössl eyepieces can be used. Their low number of optical elements results in less stray light.
The 2" Crayford Focuser
More simple telecopes have a 1.25" focuser - sometimes not even made of metal. Of course, this 2" focuser is made of metal. The drawtube is mounted on ball bearings. Even heavy cameras and eyepieces are held without effort, sensitive focusing is possible. The focuser is supplied with a reduction adapter for 1.25" barrels. 2" and 1.25" accessories are locked gently and safe by compression rings.
But what if you want to start in astrophotography, though?
Taking images of moon and planets is no problem using eyepiece projection or a barlow lens. But if you want a coma corrector and perhaps a DSLR for deep sky imaging, there are two possibilities:
1] Focuser UNCN2 - the short Crayford focuser fits directly to the existing holder and replaces the original Crayford. With 55 mm height, the UNCN2 is shorter and you have again space for standard correctors and your camera.
2] TeleVue Coma Corrector VIP-2010 - this corrector has the effect of a Barlow lens, it extends the focal length by 15% and brings the focal plane further outward. With this, you take images with all common DSLR and CCD cameras again, too.