William Optics FLT 91 Fluorostar 91mm f/5.9 Triplet Apo Refractor with Carry Case - Red
Availability: Item has been discontinued by the manufacturer
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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
| Product Banner Type | discontinued |
|---|---|
| Free Shipping Graphic | Free Contiguous US Shipping |
| Telescope Focal Length | 501 - 600mm |
| Hide Found a better Shipped Price on Frontend? | No |
- Fluorostar 91
- Vixen Saddle Plate
- Visual Extension Tube
- Handle Bar
- Built-in Bahtinov Mask Cap
- Soft Carry Case
- Note: Guidescope shown in the photo above is not included
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
| Product Banner Type | discontinued |
|---|---|
| Free Shipping Graphic | Free Contiguous US Shipping |
| Telescope Focal Length | 501 - 600mm |
| Hide Found a better Shipped Price on Frontend? | No |
- Fluorostar 91
- Vixen Saddle Plate
- Visual Extension Tube
- Handle Bar
- Built-in Bahtinov Mask Cap
- Soft Carry Case
- Note: Guidescope shown in the photo above is not included