Sharp star D150 f2.8 Astrograph

[glend]

I have run across a couple of references to to new Sharp star D150 f2.8 Astrograph. A fairly different sort of Newt, as it uses a hyperbolic primary. TS is selling a badged version as the Hypergraph 6.

https://www.teleskop-express.de/shop/product_info.php/language/en/info/p11082_TS-Optics-150-mm-f-2-8-hyperbolischer-Astrograph-mit-Korrektor-und-Carbontubus.html

There is a thread on Cloudy Nights about it as well,

https://www.cloudynights.com/topic/663055-new-sharpstar-15028hnt-initial-impression-with-pics/#entry9399184

Fairly pricey, but cheaper than an Officina Stellare. They also have a 200mm, f3.2 version which uses a parabolic primary.

Big image circle 45mm (full frame).

Reading some of the CN reviews, it seems the QA may be a bit spotty, some good, some not, mainly mechanical, screws, etc. Probably would expect more quality in that price bracket. Frankly a hyperbolic primary scares me.

[Peter Ward]

Why? RC's have hyperbolic primary and secondary optics. I have quite a nice RC that works very well ;)

There are plenty of rubbish telescopes with spherical and parabolic components out there....hence the design is rarely the issue, but if implemented poorly/cheaply , it's likely to disappoint regardless of the required curves.

[LewisM]

Tak Epsilon been a splendid performer for decades, and rarely goes off collimation. Slightly slower but not much.

[glend]

My prejudice regarding hyperbolic primaries stems from my time with a GSO RC, but i realise that other manufacturers may be better. My CC has a parabolic primary and hyperbolic secondary and it is rock solid (collimation wise).
Still the Sharpstar is an interesting scope, but niche most likely.