William Optics Fluorostar 91 (aka FLT-91) RD / red OTA (SKU: T-FLT-91RD-RP33)

The William Optics Fluorostar 91 is a cutting-edge optical instrument meticulously designed to meet the exacting demands of astrophotography. It offers remarkable image quality, surpassing most telescopes of its kind in its ability to eliminate optical defects. The visionary team of designers and engineers at William Optics spared no effort in selecting the finest materials and employing exemplary craftsmanship to create a refractor of unrivaled optical excellence, attested by its impressive Strehl coefficient of over 0.95.

At the core of this refractor lies an apochromatic triplet optical system, comprising lenses crafted from the highest quality materials, including the exceptional FPL-53 glass from renowned Japanese manufacturer Ohara. With an incredibly high Abbe number of 94.49, this refractor utilizes an extremely low dispersion material, ensuring minimal chromatic aberration. Furthermore, each lens is treated with a multi-layer anti-reflective coating, guaranteeing sharp, high-contrast images.

The Fluorostar 91's generous illumination disc diameter makes it an ideal instrument for use with full-frame sensor cameras and APS-C matrix-equipped DSLRs.

Key Features of the William Optics Fluorostar 91 Refractor:

• Apochromatic triplet optical system with lenses made from FPL-53 glass and coated with a multi-layer anti-reflective coating.
• CNC technology precision craftsmanship for secure and stable mounting.
• William Optics patented Bahtinov mask design with a convenient handle for easy adjustments.
• Full illumination circle that ensures complete coverage of full-frame sensors.

Technical Specifications:

• Optical system: ED-APO apochromatic triplet
• Objective diameter: 91 mm
• Focal length: 540 mm
• Aperture: f/5.9
• Lens material: FPL-53 glass (Ohara, Japan)
• Anti-reflective coating: Full multi-layer coating (FMC)
• Strehl coefficient: > 0.95
• Full illumination circle diameter: Suitable for full-frame sensors
• Compatible sensor sizes: APS-C, full frame
• Compatible photographic systems (via interchangeable T-rings): Canon EF, Nikon F, Sony E, Pentax, Micro 4/3, Fuji FX
• Focuser: 3.3"
• Eyepiece type: Rack & pinion, dual-speed
• Recommended flatteners: WO Flat 6A III x0.8, WO FLAT 68 III x1.0 (uniquely compatible, enabling full illumination of the corners of full-frame sensors)
• Finder foot: Vixen
• Folded tube length: 441 mm
• Extended tube length: 510 mm
• Tube weight: 4.2 kg (total weight: 5.5 kg)
• Tube finish: Red

Kit Components:

• William Optics Fluorostar 91 refractor
• Vixen mounting plate
• Bahtinov mask with mount
• Mounting bracket
• Transport bag
• Spacer tube

Guarantee:

The William Optics Fluorostar 91 comes with a 24-month warranty, ensuring your peace of mind and satisfaction with your purchase.