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Sharpstar AL-90R F/6.67 triplet apochromat FPL-53




The Sharpstar AL-90R F/6.67 apochromatic refractor is an air-spaced triplet apochromat with S-FPL53 central lens. Objective lens diameter is 90 mm with 600 mm focal length. 2.5" sturdy rack and pinion focuser with 360° rotation and 1:10 microfocuser, 2" and 1.25" adapter included. Telescope comes with sliding dew-shield, CNC rings, Vixen/GP dovetail plate, universal finder base and transport case.

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1 149,00 €

-100,00 €

1 249,00 €

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Sharpstar AL-90R F/6.67 triplet apochromat FPL-53

The Sharpstar AL-90R F/6.67 features an apochromatic objective lens with 90 mm diameter and 600 mm focal length (focal ratio F/6.67). Optical design consists is an air-spaced triplet apochromat with japanese Ohara S-FPL53 central lens delivering very high color correction. Each optical surface is fully multi-coated with a high light-transmission coating.

The Sharpstar AL-90R F/6.67 is a refractor designed mainly for astrophotography indeed: focal ratio of F/6.67 is somewhat fast, combining it with a 2" or 2.5" field flattener this refractor transforms into a flat field astrograph corrected also on big-sized sensors. You can lower down focal ratio using a reducer / flattener, such as the Riccardi 0.75x M63 Reducer, directly compatible with these instruments.

Even if the the photographic vocation of this instruments is apparent, the Sharpstar AL-90R delivers stunning performance also on visual observations. Color correction and optical quality are excellent and generous backfocus allows the use of binocular turrets without any optical corrector in the light path.

Optical tube is made from aluminium light alloys CNC machine. It has a modular design, in fact OTA can be divided in various sections in order to optimize backfocus for your needs.

The Sharpstar AL-90R F/6.67 features an oversized 2.5" rack & pinion focuser with 1:10 micro-focuser. 2" and 1.25" adapter are included. Focuser shows also an M63 thread where you can screw 2.5" correctors or focal reducer with the same thread. Focuser allows also 360° rotation.

Mechanical quality is top-notch: OTA is made with light aluminium alloy, light and sturdy. Focuser is of very good quality. Even experienced customers will admire for sure quality of this instruments. Nothing is left to chance!

Technical data

  • Optical design: air-spaced apochromatic triplet with japanese Ohara S-FPL53 central lens.
  • Aperture: 90 mm
  • Focal length: 600 mm
  • Focal ratio: F/6.67
  • Coating: yes, Fully Multi-Coated
  • Resolving power: 1.29"
  • Limit magnitude: 12.3
  • Backfocus: 180 mm
  • OTA length: 505-565mm
  • Outer tube diameter: 100 mm
  • Outer diameter of the dew-shield: 116 mm
  • OTA made of light aluminium alloys, CNC machine and divisible in 3 sections.
  • Weight: 3.2 Kg OTA only - 3.8 Kg with rings and Vixen/GP dovetail - 10.4 Kg with case included

Scope of delivery

  • 2.5" focuser with female M63x1 thread, 2" and 1.25" reductions, 1:10 micro-focuser and 360° rotation.
  • Retractible dewshield
  • Finder shoe
  • 100 mm CNC rings
  • Vixen/GP dovetail plate
  • Transport case

Optical and mechanical check before delivery

Sharpstar inspects any instrument with their interpherometer in order to deliver the highest quality possible. Any optics sold by Skypoint is thouroughly tested with our optical bench. Testing includes also a deep mechanical check so that you will be sure to get a perfectly collimated instrument without mechanical defects that may occurs during import from China.

Skypoint, thanks to his pluriannual expertize, can assis you to complete your setup. We are also able to design and manufacture high-precision mechanical adapters for your CCD or CMOS camera. Contact us for info!

We ship worldwide, contact us for a quotation

ip worldwide, contact us for a quotation!

    Leasing12 installments at zero interest

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