William Optics
Fluorostar 91
- Regular price
- $ 1,998.00
- Sale price
- $ 1,998.00
- Unit price
- per
This item is out of stock but you can place an order now and we’ll ship when it becomes available.
In StockThe 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.
RotoLock
The Rotolock 2 inch adapter provides for a solid and efficient connection for a WO 2 inch diagonal, and other accessories.
Bahtinov Mask (Patented)
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 PatentedThe 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 KnobA larger fit designed for better ergonomics. |
Field RotatorThe super smooth field rotator includes markings for every degree, and a solid thumbscrew position lock. |
 |
 |
Soft Carry CaseThe standard package comes with a soft carry case. |
Technical Specifications
| Lens Type | Apochromatic Triplet Prime Lens |
| Focal Length | 540mm |
| Diameter | 91mm |
| Aperture | f/5.9 |
| Flattener | FLAT 6A III x0.8 / FLAT 68 III x1.0 |
| Focuser | Dual Speed 3.3" R&P Focuser |
| Color | Red / Gold / Space grey |
| Lens Material | FPL-53 |
| Strehl Ratio | 0.95+ |
| Camera Format | Full Frame DSLR / Mirrorless / CMOS / CCD |
| Test Report | Zygo test report available at additional cost |
| 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 |
| Extension Tube Length | 40mm |
| OTA Weight | 4.165Kg |
| Total Weight | 5.575Kg |
| Extension Tube Weight | 0.105Kg |
What's in the Box?
Fluorostar 91
Vixen Saddle Plate
Visual Extension Tube
Soft Carry Case
Handle Bar
Built-in Bahtinov Mask Cap
Buy risk-free: When it’s time to trade up you’ll get the most value for your used gear.
