William Optics FLT 91 Fluorostar 91mm f/5.9 Triplet Apo Refractor with Carry Case - Space Gray

The FLT 91 is the perfect Apochromatic refractor for visual and photographic astronomers demanding excellence in a midsize telescope. The three-element optical design features a 91mm aperture using FPL-53 glass. The STM-coatings and superb quality provide excellent optical performance and unmatched value.

Features:

• Rotolock: The Rotolock 2 inch adapter provides for a solid and efficient connection for a WO 2 inch diagonal and other accessories.
• Bahtinov Mask: The retractable dew shield features a removable lens cover, with our patented Bahtinov Mask revealed by unscrewing the face plate. The clear design allows for brighter star patterns and precise focusing for astrophotography.
• Versatile Saddle Bar: The Saddle Bar Handle offers a solid handle with a built in dovetail chamber for use with the WO Uniguide scopes or other Vixen style guiding/finder scopes.
• New Focuser Knob: A larger fit designed for better ergonomics.
• Field Rotator: The super smooth field rotator includes markings for every degree and a solid thumbscrew position lock.
• Soft Carry Case: The standard package comes with a soft carry case.

Specifications:

• Lens Type: Apochromatic Triplet Prime Lens
• Focal Length: 540mm
• Diameter: 91mm
• Aperture: f/5.9
• Recommended Flatteners (Not included): FLAT 6A III x0.8  FLAT 68 III x1.0 (use of the Flat68III requires the use of a special adapter that is sold separately)
• Focuser: Dual Speed 3.3" R&P Focuser
• Lens Material: FPL-53
• Strehl Ratio: 0.95 or higher guaranteed (Scope with Strehl of 0.98+ available by special order for $450 more - check availability with us before placing any order)
• Camera Format: Full Frame DSLR / Mirrorless / CMOS / CCD
• Test Report: Zygo test report available at additional cost after purchase (not available before or with purchase)
• 48mm Wide T-Mounts Supported:
  • Canon EF, RF
  • Nikon F, Z
  • Sony E
  • Pentax K
  • Micro Four Thirds (M4/3)
  • FUJI X
• Retracted Length: 441mm
• Extended Length: 510mm
• Dew shield OD: 121mm / 4.76"
• Extension Tube Length: 40mm
• OTA Weight: 4.165Kg
• Total Weight: 5.575Kg
• Extension Tube Weight: 0.105Kg