Sharpstar 121mm f/5.6 ED Quintuplet Apo Refractor Telescope # 121SDQ
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Please Note:
- All Sharpstar/Askar refractors undergo physical, mechanical and optical QC inspections at the factory, and an inspection checklist is included with each telescope.
- We may partially open the scope boxes to ensure that the scope has been inspected/certified by the manufacturer but we do not open the scope and inspect it again.
- However, if you would like us to perform a mechanical and cosmetic inspection of your telescope again before we ship it, just request this in the comments field when you place your order. We will be happy to do this at no extra cost for this scope, but this will delay your shipment by 1-2 business days. Note that we are unable to perform optical tests/inspections.
Product Details
The Sharpstar 121 SDQ is a apochromatic Petzval quintuplet refractor with a focal ratio of f/5.6. The air-spaced triplet objective includes one ED glass element, while the rear doublet acts as corrector and field flattener.
Using a fixed two-element corrector in the optical tube means the user does not have to set the camera at a specified position relative to the flattener, which is unlike the case with external field flatteners and focal reducers. This allows the freedom to use a wide range of accessories such as filter wheels or off-axis guiders in front of the sensor without concern about the correct distance between flattener and sensor. The Sharpstar 121SDQ has a generous 145mm of working distance.
The large 4" brass rack-and-pinion focuser is fully rotatable by 360° to perfectly frame the subject, and it has a precise dual-speed 10:1 focusing mechanism for precise focus control. The focuser supports a big 7.5kg payload and the drawtube has an opening for standard 2" diagonals and accessories with 110mm of focuser travel.
All five lenses in the telescope are fully multi-coated and the aluminum tube is internally blackened to reduce reflections and absorb stray light. All mechanical components of the Sharpstar 121 SDQ are engineered to provide the best rigidity, performance and durability.
The 60mm fully-corrected image circle is large enough for a medium format camera, and a focal length of 678mm makes this a perfect fast astrograph for the advanced astrophotographer.
For the price, this fast apochromatic telescope offers excellent value and can approach the performance of telescopes that cost three or four times as much. This is especially true when matched with astronomy cameras with smaller 1" and 4/3" sensors. Cameras with larger APS-C and full-frame sensors may reveal slight aberrations at the edge of the field, especially when using the focal reducer.
The telescope also includes a Vixen/Synta-style finder mounting base (finder not included), tube rings, a Losmandy/D style mounting rail (180mm long), a convenient carrying handle, a metal objective dust cover, and a protective hard case. No 1.25" eyepiece adapter is included.
OTA Specifications:
- Aperture: 121mm
- Focal Length: 678mm
- Limiting Star Magnitude: 12.1
- F Ratio: f/5.6
- Resolution: 0.97 arc seconds
- Objective Type: Quintuplet Air-Spaced Apochromatic
- Back Focus: 145mm (from thread of focuser end
- Net Weight: 7.98kg (8.92kg including tube-ring, dovetail plate, handle)
- Length: 698mm (DewShield Extended), 598mm (DewShield Retracted)
- Tube Outside Diameter: 130mm
- Dewshield Outside Diameter: 160mm
Other Information
- Country of Manufacture: China
