William Optics Fluorostar 91 Apochromat

The FLT 91 is the perfect apochromatic refractor for visual and photographic astronomers who demand the most from a medium-sized telescope. The three-element optical design offers an aperture of 91 mm and uses FPL53 glass. The STM coatings and superior quality provide excellent optical performance and unsurpassed value.

Features of the Fluorostar 91

RotoLock
Rotolock 2-inch adapter provides a solid and efficient connection for a WO 2-inch prism and other accessories.

Versatile handle with prism clamp
The grip bar provides a solid handle with a built-in finder shoe for use with WO Uniguide guide tubes or other Vixen standard guide/finder tubes.

Image field rotator
The super-lightweight field rotator includes degree-accurate markings and a solid thumbscrew for position locking.

Bahtinov mask
The retractable dew cap features a removable lens cover, with WO's patented Bahtinov mask revealed by unscrewing the front cover. The transparent design allows brighter star imaging and precise focusing for astrophotography.

New focusing knob
A larger design provides better ergonomics.

Carrying case
A soft carrying case is included as standard.

The FLT 91 is the perfect apochromatic refractor for visually and photographically observing astronomers who demand the most from a medium-sized telescope.

• Three-element design with FPL53 glass
• 91 mm aperture, 540 mm focal length
• Rack and pinion focuser with gear reduction and "Rotolock" clamp
• Field rotator with degree markings and position lock
• Prism rail according to Vixen standard
• Versatile handle with Vixen standard finder shoe
• William Optics' patented Bahtinov mask