Telescope-Refracting Telescopes-William Optics Space Gray Fluorostar 91 Triplet APO Refractor with 3.3″ Rack & Pinion Focuser and Ultra Flat Reducer

Superb FPL-53 Triplet Optics
The FLT91 refractor uses a triplet optical
design, which provides chromatic-aberration correction. Ensuring your views
will be apochromatic and tack-sharp, William Optics has used FPL-53 glass in
this design, which provides this enhanced performance through its super ED
characteristics. With a 91 mm front aperture and f/5.9 focal ratio, this
scope offers bright views and a 540 mm focal length window into the
universe.

Astro Photo Adaptation: Ultra Flat 91
For those looking to
maximize the astrophotography performance of the Fluorostar 91, the excellent
William Optics Ultra Flat 0.79x Reducer
is included in this bundle! This corrective element integrates seamlessly with
the FLT91, replacing the 2″ RotoLock for a secure a sleek connection. With a
0.79x reduction factor this transforms your scope into a
wider FOV, brighter, and full-frame corrected astrophotography
powerhouse; providing a f/4.7, 424 mm focal length view into the night sky across a
43.2 mm image circle. This corrective element requires 56.18 mm of
backfocus for best performance.

Robust Rack and Pinion Focuser
For comfortably carrying today’s sometimes
quite stout and demanding equipment trains, the FLT91 comes equipped with a
large 3.3″ rack and pinion focuser! This features a massive M92 connection
to provide an obstructed view for either the included 2″ RotoLock or the
dedicated Ultra Flat 0.79x Reducer (sold separately) and a dual-speed focus
knob for precisely finding your perfect image or view. For those looking to
add a more automated focusing system, this focuser can accept bracket style
electronic focusers like the
ZWO Standard Electronic Automatic Focuser
right out-of-the-box. Finally, for simple framing adjustments and gear
rotation, this has an integrated 360° rotator; simply loosen the
thumbscrew, adjust your gear, then snug down the thumbscrew to lock your
gear in place.

Fast 2″ Accessory Changes
Where more conventional visual backs feature
thumbscrews, the Fluorostar 91 features William Optics’ RotoLock for quicker
2″ eyepiece and equipment swaps. With just a short twist the RotoLock can be
loosened to remove your current eyepiece or accessory and then re-locked
with a quick twist back. This system is more than just convenient, featuring a
solid lock up to ensure your equipment changes are speedy and secure!

Included Accessories
The William Optics Fluorostar 91
FPL53 Triplet APO Refractor with 3.3″ Rack & Pinion Focuser comes with a
number of essential and handy accessories that make it a solid foundation
for a wide variety of imaging and observing builds. A pair of anodized
rings hold the FLT91 securely to the V-style connection, extended width, dovetail
bar and the dual-function handle/findershoe base accessory top
rail. These feature large knobs to make removing the scope or adjusting it a
breeze. For the astrophotographer, this scope also sports William Optics’
excellent Bahtinov mask dust cap—featuring a focusing screen behind a
removable front cap that makes nailing focus simple. This scope also
features an analog thermometer coarse focus knob, for a bit of added
functionality and scientific flair! Finally to make storage and transport
simple and secure, William Optics has included a foam padded soft carry
case.