William Optics Gold Fluorostar 91 Triplet APO Refractor with 3.3" Rack & Pinion Focuser and Ultra Flat Reducer
A Premium Astrophotography Package—The William Optics FLT91 and 0.79x Ultra Flat Reducer!
With 91 mm of aperture the William Optics Fluorostar 91 sits in the "mid-sized" space of the company's fantastic refractor offerings, but its performance is anything but middling! With premium optical elements used in its triplet design, this scope provides stunning apochromatic images which are further refined with the included dedicated FLT91 0.79x Ultra Flat Reducer for stellar full-frame corrected views. Experience powerful, fully featured, refractor performance, with the William Optics Fluorostar 91 FPL53 Triplet APO Refractor with 3.3" Rack & Pinion Focuser and Ultra Flat Reducer!
At the heart of the William Optics Fluorostar 91 (FLT91) refractor is a triplet optical design. With FPL-53 glass used, this three lens design is able to provide impressively sharp and apochromatic images for clear, color-fringing-free, views. Maximizing this performance for astrophotography is the included Ultra Flat 0.79x Reducer. Designed for the FLT91 refractor, this reducer provides a wider and brighter perspective on deep sky targets. Allowing you to more comfortably frame larger objects like Andromeda Galaxy or the Orion Nebula, this reducer additionally provides a well-corrected full-frame image circle. Building on this strong foundation, William Optics has included an excellent set of supporting hardware: premium gold anodized aluminum rings, a V-style dovetail with an extended with top plate, dual-function handle and Synta accessory mount top rail, large 3.3" rack and pinion focuser, 360° rotator, and a RotoLock 2" visual back! This all adds up to a powerful and fully-featured refractor capable of providing stunning views and images of larger deep sky objects!
A Premium Mid-Size Triplet Refractor
Featuring premium triplet optics, a quick and secure 2" visual back, rock solid focuser, dedicated astrophotography accessories, and all the essential hardware you need, the William Optics Fluorostar 91 FPL53 Triplet APO Refractor makes a strong case for the optical core of your next astronomy rig!
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.
Astronomy Hub: Your one-stop-shop for Astrophotography Knowledge!
Our Gear Experts have compiled a wealth of information to help expand your astrophotography knowledge! Below you’ll find links to articles, videos and "how-to" guides. Just one more reason that our Astronomy Hub is a one-stop-shop for all your astronomy and astrophotography needs!
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