William Optics Fluorostar 91
- 91mm APO using FPL-53 Glass
- F/5.9 Fast Focal Ratio
- Portable and Versatile
Take your astrophotography to new heights with the William Optics Fluorostar 91, a premium APO refractor telescope designed to capture the beauty of the night sky with unparalleled precision. With its fast f/5.9 focal ratio and advanced optical design, this instrument is perfect for astrophotographers and astronomers seeking to explore the depths of the universe.
Avoid Looking Directly at the Sun:
Use only with a proper solar filter, such as a front-mounted filter .
The Rotolock 2 inch adapter provides for a solid and efficient connection for a WO 2 inch diagonal, and other accessories.

The Fluorostar 91 boasts a larger fit focuser, designed for smooth and precise focusing, allowing you to capture images with ease and accuracy.


The Fluorostar 91 comes with a soft carry case to make your astrophotography journey seamless:
|
Lens Type |
Apochromatic Triplet Prime Lens |
|
Focal Length |
540mm |
|
Diameter |
91mm |
|
Aperture |
f/5.9 |
|
Focuser |
Dual Speed 3.3" R&P Focuser |
|
Color |
Red 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 |