SHARPSTAR 150 HNT HYPERBOLIC ASTROGRAPH F/2.8
Sharpstar
Hyperbolic Newtonian
5.95 kg
SHARPSTAR 150 HNT HYPERBOLIC ASTROGRAPH F/2.8 is backordered and will ship as soon as it is back in stock.
The Sharpstar 150HNT is an astrograph with the ultra fast focal ratio of f/2.8 and a focal length of 420mm. Different from the Newton optical design, this telescope installs a hyperbolic primary mirror, a large 70mm secondary mirror and a 3 elements corrector to be placed before the focal plane. The optical design delivers a 44mm fully illuminated and corrected image circle for large sensors such as the full frame (24x36mm).
The mirror is made of H-PZ33 borosilicate glass with a similar low expansion thermal coefficient of the Pyrex. The enhanced aluminum mirror coating ensures a reflectivity over 96%. The large 70mm secondary mirror is rigidly kept in place by the monopiece secondary mirror spider that does not bend or twist.
The large rack and pinion 2.5" focuser can be rotated 360°and it has a reduction gear of 1:10 for precise focusing. The focuser is compatible with the ZWO EAF electronic focuser bracket.
All the lenses used in the corrector are fully multi-coated and the tube is internally blackened to reduce reflections and absorb stray light.
The tube is made of carbon fiber, the rack and pinion focusing mechanism of brass and the mechanical components are engineered to provide the best rigidity, performance and durability.
This telescope works at its best with its own focal reducer and corrector delivering a fully corrected field of view for the full frame sensors. The CCD inspector results shows that across the entire full frame this telescope produces a "curvature" of only 18.8%. That means at the corner of a full frame sensor, stars are only 18.8% larger than in the center. For more information about CCD Inspector, please read this article in the Testar blog.
CCD Inspector results with SharpStar 150 HNT.
The maximum vignetting for the full frame is less than 20% at the corner of the sensor.
Specifications
| Optical design |
Hyperbolic reflector with integrated corrector |
|
Objective diameter |
150 mm |
|
Focal length |
420 mm |
|
Focal ratio |
f/2.8 |
|
Secondary mirror |
70 mm (minor axis) |
|
Obstruction |
46.7% |
|
Resolving power |
0.80 arc second |
|
Stellar limiting magnitude |
12.9 |
|
Max. magnification |
375 x |
|
Light gathering power |
459 times the human eye |
|
Mount attachment |
Losmandy style bar (200 mm) |
|
Focuser |
Rack & pinion, dual speed (10:1) 2.5" diameter |
|
Camera connection |
M48 x 0.75 male |
|
Corrector distance |
55 mm |
|
Tube weight |
5.95 kg (including tube rings and dovetail bar) |
|
Tube length |
445 mm |
|
Tube diameter |
195 mm |
|
Tube material |
Carbon fiber |
|
SKU |
SS-15028HNT |
Included Items
- SharpStar 150 HNT f/2.8
- 196mm tube rings
- 200mm Losmandy style dovetail bar
- Handle on the rings
- Adapter to 2" and 1.25"
- Foam-lined aluminium case
Gallery
M31 - Sharpstar 150 F/2.8 Astrograph
NGC6726 - Sharpstar 150 F/2.8 Astrograph - © Davide Mancini
M8 & M20 - Sharpstar 150 F/2.8 Astrograph - © Davide Mancini
NGC7293 - Sharpstar 150 F/2.8 Astrograph - © Davide Mancini
