William Optics Fluorostar 91 Triplet Refractor

This beautiful 91 mm f/5.9 APO Triplet refractor is decked out and ready to ride on your telescope mount!  Whether you want to do visual astronomy, astrophotography, terrestrial observing or wildlife photography, this is the scope for you!  The FLT91 is designed from the optics down for a quality experience.  The optics are housed in a steel lens cell and consist of three elements (triplet) made of fully multi-coated Ohara FPL-53 glass.  Contrast, clarity and virtually color-free results will boost your visual and astro-imaging to a new level.

The 3.3-inch dual-speed rack & pinion focuser is built to hold the weight of a camera and other equipment, like the dedicated FLT91 0.8X Reducer and Field Flattener, without flexing.  A super smooth field rotator is included to make it easier to frame the perfect shot, and it has markings every degree for repeatable results.  

The William Optics Rotolock goes way beyond your typical 2" adapter, and will provide a very solid connection, whether you insert a 2" diagonal or other accessories.

On the front end of the FLT91 you will find a custom Bahtinov mask that is connected to the removable lens cover.  It is easy to reveal the mask for precision focusing and then store it away again in the lens cover until you need it again.

You will also receive beefy mounting rings that connect to an included (and matching!) Vixen-style dovetail plate.  The rings have a built-in handle/saddle bar on top to make it easy to carry and set up your FLT91...William Optics has thought of everything!  If you'd like to ride a guide scope or finder on top, this patented saddle bar handle will accept the William Optics Uniguide as well as other Vixen-style finders or guidescopes.

Finally, the William Optics FLT91 comes with a soft carry case, allowing you to protect your telescope when not in use or when traveling to the perfect dark-sky site or terrestrial wonder.  

PLEASE NOTE:  The FLT91 is available in Red, Gold, or Space Gray.  The pictures show mostly the red version (which is a knock-out!).  There are a few images of the Space Gray model, but none of the Gold.  If you are not sure what it looks like, search for the Gold version of other William Optics scopes...the color is the same.

 Technical Specifications

Lens Type:  Apochromatic Triplet Prime Lens
Focal Length:  540mm
Aperture:  91mm
Focal Ratio:  f/5.9
Focuser:  Dual Speed 3.3" R&P Focuser
Lens Material:  Ohara FPL-53
Strehl Ratio:  0.95+
Camera Format:  Full Frame DSLR / Mirrorless / CMOS / CCD
Retracted Length:  441mm
Extended Length:  510mm
Extension Tube Length:  40mm
OTA Weight:  4.165Kg
Total Weight:  5.575Kg
Extension Tube Weight:  0.105Kg