TS-Optics GSO 6" f/12 Cassegrain telescope 154/1848 mm OTA

TS-Optics GSO 6" f/12 Classical Cassegrain Telescope

Cassegrain telescopes combine the benefits of a Newtonian telescope being a pure reflective system with a short-built design. In terms of optical quality, Cassegrain telescopes are superior to customary Schmidt-Cassegrain systems. Cassegrain telescopes are mainly used for photography of the moon and the planets and for observation of astronomical objects. Thanks to the highly sensitive sensors built into modern astro cameras, even deep-sky photography of nebulae, star clusters and galaxies is possible.

The advantages of the TS-Optics Cassegrain telescopes in summary:

♦ Less field curvature than with SC telescopes.
♦ Pure reflection system without Schmidt plate, as a result even Infrared photography becomes possible at full sharpness.
♦ Significantly quicker temperature adaption than a SC, due to open design.
♦ Brighter image due to 96% dielectric coating on primary and secondary mirror.
♦ No shifting, because the primary mirror is fixated
♦ High-quality 2" Crayford focuser with micro-gear reduction and compression rings for 2" and 1.25" accessories
♦ 38% obstruction caused by secondary mirror, comparable to SC telescopes.
♦ Better sharpness on the optical axis due to precise mirror surfaces and the lack of a Schmidt plate
♦ Less problems from dew: with Schmidt-Cassegrains you get condensation on the front plate, not with a Cassegrain
♦ Interior baffles for even higher contrast
♦ Generous backfocus allowing the use of 2" accessories.
♦ Compact tube with only 500 mm length - can be operated with smaller mounts
♦ Significantly less expensive than other classical Cassegrain telescopes!

The TS-Optics Cassegrain is a versatile telescope

♦ Mobile travel scope: Take the compact and light telescope with you to your traveling location. It only takes a few seconds to unscrew the focuser, making the Cassegrain even more compact and fitting your hand luggage.

♦ Telescope for observation of astronomical objects: Due to the bright and contrasty image and also because of the large corrected and illuminated image field, the Cassegrain is optimal for observation of astronomical objects. 2" and 1.25" accessories are not a problem. The obstruction by the secondary mirror is only 38%. This is comparable to Schmidt-Cassegrain telescopes. As a result of the 96% reflection of primary and secondary mirror the image is significantly brighter. Even the field sharpness is better, because the image field is basically undistorted.

♦ Telescope for astrophotography: The Cassegrain is very well suited for photography of the moon and the planets. The visual contrast is very high. Due to interior baffles stray light is effectively suppressed. Planets and tiny moon craters can be seen without the slightest chromatic aberration. Thanks to its micro-gear reduction the Crayford focuser permits precise focusing.

Astrophotographic results obtained with this telescope on Astrobin

Here you can find some astrophotographs made with this telescope model: Link to Astrobin

♦ 6" f/12 Cassegrain
♦ 2" focuser with reduction to 1.25"
♦ Dovetail GP Level
♦ Dust protection cap for the focuser and front aperture
♦ Finder shoe (mounted)
♦ M90 extension tubes
♦ German collimation manual

 
The newest reviews:

(1 review)

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2020-10-19 20:28:09, Fedotov Mikhail

12 days delivery time to Moscow - super fast. The tube itself is heavier than expected - with CG-4 mount suitable for visual observation only, even with anti-vibration pads the vibration on high mags take several seconds to subdue, for astrophoto - EQ5 is what you need at least, AVX will be optimal. The optical performance is superb - star test reveals no significant aberrations or defects, pre-focal and after-focal pictures are identical, the optics are diffraction limited. Holds 2x magnification very easy (even easier than my SW DOB 8) - very sharp and detailed image on 308x. A true planetary scope. The build quality is mediocre - half of the screws were loose, make sure you have checked every one of them before using the scope. Also the tube arrived completely out of collimation, such misalignment can't be blamed on post alone, the tube wasn't collimated prior to delivery. Collimation is relatively easy. Trickier than on newtonian since laser collimator is useless, easier than on refractor or RC. The focuser is smooth and precise, and you can rotate it 360 degrees - very pleasant to use on equatorial mount. The biggest advantage of this cassegrain (next to image quality) is its open design and quartz optics - cooldown on 20 degree temperature difference takes roughly an hour - super fast compared to maks and SCs of the same size. The main drawback is the sizing of spacers for visual use - 2" + 2" diagonal mirror is too long for 40 mm WO SWAN eyepiece, 1" is too short for everything else I have. 1.8-1.9" spacer would be just perfect. The seconday obstruction is noticeable - stars in focus have that circle around them, and planets have a glowing orb. The secondary mirror wanes are also quite thick - bright stars have 4 spikes with brigtness higher than I would prefer. But considering the price of 340 EUR all that is forgiveable. All in all - a great planetary and grab&go machine.
 
 

Astrophotographic results obtained with this telescope on Astrobin

Here you can find some astrophotographs made with this telescope model: Link to Astrobin