William Optics Fluorostar 91 FPL53 Triplet APO Refractor with 3.3" Rack & Pinion Focuser - Red

William Optics Fluorostar 91 Triplet APO Refractor Telescope with 3.3" Rack & Pinion Focuser

Astronomers desirous of superb visual and photographic intermediate sized refractor performance will much appreciate the William Optics 91 mm f/5.9 Fluorostar. The FLT 91 employs FPL-53 glass and has an optical design consisting of three elements. ln addition, with STM-coatings enabling superb optical performance, the FLT 91 provides excellent quality that is tough to match.

RotoLock Adapter

A dependably effective 2" William Optics diagonal or accessory to FLT91 connection is provided by the RotoLock 2" adapter.

Bahtinov Mask

Uncover William Optics' patented Bahtinov Mask by detaching the face plate from the retractable dew shield lens cover. Experience brighter star patterns and accurate focusing for astrophotography via the Mask's clear design.

Versatile Saddle Bar

In addition to its compatibility with any Vixen-style guidescope or finderscope including the WO Uniguide, the versatile Dovetail Saddle Bar also features a sturdy handle for a solid grip.

New Focuser Knob

Focuser knob design is larger and more ergonomic for enhanced comfort during use.

Field Rotator

This exceptionally smooth field rotator with solid thumbscrew position lock contains markings for every degree.

Soft Carry Case

A soft carry case comes standard with the William Optics Fluorostar 91.

William Optics Fluorostar 91 Triplet APO Refractor Technical Specifications

• Lens Type: Apochromatic Triplet Prime Lens

• Focal Length: 540 mm

• Aperture: 91 mm

• Focal Ratio: f/5.9

• Focuser: Dual-Speed 3.3" Rack & Pinion

• Color: Red

• Lens Material: FPL-53

• Strehl Ratio: 0.95+

• Camera Format: Full Frame DSLR/Mirrorless/CMOS/CCD

• Supported T-Mounts: Canon EF, RF/Nikon F, Z/Sony E/Pentax K/Micro Four Thirds (M4/3)/Fuji X

• Retracted Length: 441 mm

• Extended Length: 510 mm

• Extension Tube Length: 40 mm

• OTA Weight: 9.2 lbs. (4.165 kg)

• Total Weight: 12.3 lbs. (5.575 kg)