The Bintel 6 Inch f/5 OTA is an affordable mid sized Newtonian optical tube with great features.
It has a 150mm x 750mm primary mirror made by GSO in Taiwan and is guaranteed to provide superb images. All GSO Newtonians feature well corrected parabolic mirrors. Unlike many other companies all of their optics are tested during polishing and figuring to meet very exacting tolerances of at least 1/12th lambda or better on the mirror surface.
The 6 Inch f/5 OTA has a 750mm focal length so it is versatile for visual observations. Higher magnifications are possible without resorting to very short focal length eyepieces. At the same time a 32mm eyepiece can still provide 28x magnification with just under 2° field of view.
Supplied with a 6×30 achromatic finder and bracket, cast metal tube rings and narrow (Vixen style) dovetail plate.
It weighs only 6kg with tube rings and dovetail and is 850mm in length making the Bintel 6 Inch f/5 OTA very managable. It mounts easily on mounts such as the Skywatcher EQ3 deluxe, EQ5 and Celestron Advanced VX mount. The combined total cost of such a package is very affordable. Stepping up to 8″ and larger Newtonians also requires a larger and therefore more expensive mount.
Bintel 6 Inch f/5 OTA – Optimized for Visual Observing
Unlike many Newtonian’s made with oversized secondary mirrors, this OTA has a small secondary mirror optimized for viewing. The Bintel 6 Inch f/5 has a 45mm secondary mirror with the result being superior contrast. This is especially valuable if you want to see the finest detail in low contrast areas such as planetary detail or faint extensions of nebulosity in deep sky targets.
Another benefit of the f/5 focal ratio is that coma is far less problematic so you don’t have to use a coma corrector. It is still suitable for lunar and planetary imaging but not for imaging using larger sensors.
It has a terrific 2″ Crayford focuser allowing the use of 1.25″ and 2″ eyepieces.