• Experience our best optical performance with EdgeHD’s aplanatic, flat field Schmidt-Cassegrain optics for pinpoint stars all the way to the edge of today’s largest imaging sensors and widest eyepieces
• Aluminum optical tube with tube vents featuring an integrated 50-mesh filter allows hot air to be released from behind the primary mirror. Mirror support knobs hold the mirror in place and reduce image shift during imaging
• Versatile design accommodates 3 focal ratios: native f/11, f/7 with the addition of a focal reducer, or ultra-fast f/2 imaging with a removable secondary mirror and third-party accessories
• Celestron’s premium StarBright XLT coatings provide maximum light transmission
• A 9x50 finderscope, 2” mirror diagonal for more comfortable viewing, and wide-angle 23mm Luminos 2" eyepiece are all included

• The ultimate portable astrophotography telescope with Bahtinov mask built into the cap for quick and easy focusing.

• 43 mm image circle is perfect for full-frame cameras in this 51 mm aperture petzval refractor. 
• The f/4.9 focal ratio allows for fast light-gathering power on this wide-field telescope.
• Includes the Iconic Soft Cat Carry Case.

William Optics Guide Star 61 APO

(Soft Carry Case included)

• Provides a full-frame image circle
• Rotatable 2" manual drawtube for coarse focusing
• Rotating dewshield for fine focusing
• Comes with a free high-quality soft case

Features

• Coma free, chromatic aberration-free, spherical aberration-free optics
• 150mm (6") optical aperture
• 1370mm focal length
• f/9 focal ratio
• Fixed primary
• Low thermal expansion quartz mirrors
• Multiple knife-edge baffle system
• 2" dual-speed Crayford focuser
• Finder scope base and dovetails bar
• Optional finder scope, diagonal and 1.25" eyepiece
• Optional iOptron Electric Focuser (#8451)

Package includes
#6111 6" RC OTA only

• OTA w/2" dual speed Crayford focuser
• 2X25mm, 1X 50mm focus extension
• 1.25" accessory adapter
• Vixen dovetail bar

• 6" Schmidt-Cassegrain optical tube assembly (OTA)
• Features Celestron's premium patented StarBright XLT optical coatings
• 1500 mm focal length (f/10)
• Tube constructed of durable and lightweight aluminum

• Experience our best optical performance with EdgeHD’s aplanatic, flat field Schmidt-Cassegrain optics for pinpoint stars all the way to the edge of today’s largest imaging sensors and widest eyepieces.
• Aluminum optical tube with tube vents featuring an integrated 50-mesh filter allows hot air to be released from behind the primary mirror. Mirror support knobs hold the mirror in place and reduce image shift during imaging.
• Versatile design accommodates 3 focal ratios: native f/10, f/7 with the addition of a focal reducer, or ultra-fast f/2 imaging with a removable secondary mirror and third-party accessories.
• Celestron’s premium StarBright XLT coatings provide maximum light transmission.
• A 9x50 finderscope, 1.25” mirror diagonal for more comfortable viewing, and 40 mm Plössl 1.25” eyepiece are all included.

Gran Turismo 81 , f/5.9 OTA. FPL53 three-element APO, 2.5” R&P Focuser in Space Gray

• GT81 APO
• 2" & 1.25" Adapter Included
• Bahtinov Mask Included
• STM Multi-Coated Lenses
• f/5.9
• This is the Space Grey version

Optical Performance

The Gran Turismo 81 is a Three Element Designed APO refractor. Using FPL-53 glass this telescope provides excellent aberration correction.

Details and Features

2.5" R&P Focuser

The 2.5" R&P Focuser is smooth, stable, and reliable! No image shifting!

New Designed Rotator

William Optics designed camera angle rotator. Smooth and stable.

CNC Handle Bar

Made by CNC with anodizing. Strong and nice look!

Bahtinov Mask

World first built in clear Bahtinov mask!

Step up your astrophotography game with the William Optics RedCat 91, an advanced apochromatic refractor tailored for full-frame and medium-format cameras. This latest addition to the RedCat series combines portability with superior optical performance, making it a versatile tool for capturing breathtaking detail in deep-sky objects.

Highlights:

Petzval Design, No Backfocus Hassles
The 5-element Petzval design eliminates the need for backfocus adjustments, providing sharp, edge-to-edge images with pinpoint stars—ideal for wide-field and detailed astrophotography alike.

Full-Frame & Medium-Format Ready, No Extra Flattener Needed
With a large 55mm image circle, the RedCat 91 is perfect for both full-frame and medium-format cameras. Its advanced optics achieve flat-field images without requiring an additional flattener, giving astrophotographers the freedom to capture expansive views with unparalleled clarity.

Fast f/4.9 Focal Ratio
The RedCat 91's fast f/4.9 focal ratio is designed for bright, vivid captures of galaxies, nebulae, and beyond, ensuring excellent light-gathering power and sharp detail even on faint celestial objects.

Seamless WIFD Focusing
Equipped with William Optics' WIFD focuser, the RedCat 91 provides precise, stable focusing without additional adjustments, enhancing the ease of use for both seasoned astrophotographers and beginners.

The RedCat 91 blends the trusted RedCat heritage with William Optics’ innovative design, making it the ultimate choice for those ready to elevate their night-sky explorations.

EVOSTAR-72ED DS-PRO (OTA)
72MM (2.83”) F/5.8 ED APOCHROMATIC REFRACTOR TELESCOPE - Compact and Portable Optical Tube for Affordable Astrophotography and Visual Astronomy

sw_evostar_72ed

This high-end Evostar-72ED features a doublet objective lens with one Extra-Low Dispersion (ED) glass element. 

Each air-to-glass surface has multiple anti-reflection coatings applied to ensure optimum light transmission, approaching 99.5%! 

Sky-Watcher proudly claim their proprietary 'Metallic High-Transmission Coatings' (MHC) are the finest photon anti-rejection coatings in their class. 

An optically-matched 0.85x reducer is available for imaging at f4.9! 

(Please note the Evostar-72ED Apo has a different objective lens glass combination to the Evostar-80ED/100ED/120ED models). 

• EXPERTLY MATCHED GLASS: The EvoStar series features a matched doublet objective including one synthetic fluorite element, providing excellent color correction for visual and photographic uses.
• OUTSTANDING COLOR CORRECTION: Using the finest quality glass and proprietary Metallic High-Transmission Coatings (MHTC), EvoStar refractors produce tack sharp images with accurate color and minimal aberrations.
• PORTABLE TRAVEL SIZE: Using a compact design, this refractor is easy to transport and lightweight to support, making it the perfect travel companion.
• EVOLVES WITH SKILL: No need to replace this telescope as your skill set evolves. Whether you’re a seasoned astrophotographer or a budding novice, EvoStar refractors are versatile enough to use as your primary optical tube as your skill set improves.
• 10:1 DUAL-SPEED FOCUSER: No matter the eyepiece or camera, finding focus is a breeze with this 10:1 dual-speed Crayford-style focuser.
• EVERYTHING YOU NEED: The EvoStar 72 comes complete with an aluminum case, tube rings, and a Vixen-style dovetail.

Sky-Watcher 0.85x Reducer/Flattener for EvoStar 72ED

• Compatible with both APS-C and full frame sensors, APS-C (crop sensors) and smaller recommended
• 55mm back focus
• Drops f/ratio from native f/5.8 (420mm) to f/4.93 (355mm)
• Reduces exposure time by 38% compared to native f/5.8
• 5.8 x 3.87-degree field of view when used with a full frame camera
• 3.79 x 2.53-degree field of view when used with APS-C crop sensor 
• Includes thread-on adapter to mount reducer to Evostar 72ED focuser

• For Astrophotography/Astroimaging
• Virtually Eliminate Spherical Aberration
• Shortens Focal Ratio from f/5.8 to f/4.9
• Reduces Exposure Times by 38%
• Use with APS-C and Full Frame Cameras
• 55mm Back Focus

Sky-Watcher Esprit 120mm ED Triplet APO Refractor

Esprit 80ED, 100ED, 120ED and 150ED Super APO triplets have a doublet field flattener to get a flat field and minimize aberration and distortion.

• Aperture: 119 mm or 4.7-inch.
• Focal Ratio: f/7.
• Highest magnification of 283x.
• 9 x 50 Optical Finder included.
• 43 mm Image Circle.

Gran Turismo 81 , f/5.9 OTA. FPL53 three-element APO, 2.5” R&P Focuser in Gold

• GT81 APO
• 2" & 1.25" Adapter Included
• Bahtinov Mask Included
• STM Multi-Coated Lenses
• f/5.9
• This is the Gold version

Optical Performance

The Gran Turismo 81 is a Three Element Designed APO refractor. Using FPL-53 glass this telescope provides excellent aberration correction.

Details and Features

2.5" R&P Focuser

The 2.5" R&P Focuser is smooth, stable, and reliable! No image shifting!

New Designed Rotator

William Optics designed camera angle rotator. Smooth and stable.

CNC Handle Bar

Made by CNC with anodizing. Strong and nice look!

Bahtinov Mask

World first built in clear Bahtinov mask!

Gran Turismo 81 , f/5.9 OTA. FPL53 three-element APO, 2.5” R&P Focuser in Red

• GT81 APO
• 2" & 1.25" Adapter Included
• Bahtinov Mask Included
• STM Multi-Coated Lenses
• f/5.9
• This is the Red version

Optical Performance

The Gran Turismo 81 is a Three Element Designed APO refractor. Using FPL-53 glass this telescope provides excellent aberration correction.

Details and Features

2.5" R&P Focuser

The 2.5" R&P Focuser is smooth, stable, and reliable! No image shifting!

New Designed Rotator

William Optics designed camera angle rotator. Smooth and stable.

CNC Handle Bar

Made by CNC with anodizing. Strong and nice look!

Bahtinov Mask

World first built in clear Bahtinov mask!

William Optics RedCat 51 Gen 2 f/4.9 APO Refractor Telescope - L-RC51II

• The ultimate portable astrophotography telescope with Bahtinov mask built into the cap for quick and easy focusing.

• 43 mm image circle is perfect for full-frame cameras in this 51 mm aperture petzval refractor. 
• The f/4.9 focal ratio allows for fast light-gathering power on this wide-field telescope.
• Includes the Iconic Soft Cat Carry Case.

William Optics ZenithStar 61II Doublet Refracting Telescope - Gold

Features

• 61 mm (2.41-inch) Aperture.
• f/5.9 Focal Ratio.
• 3.2 lb - Travel Telescope for Astrophotography and Wildlife Photography.
• Adaptable with any DSLR.
• This is the Gold Version
• Innovative Bahtinov Mask Cover for Easy Focus Assist.
• Soft Carry Case Included!

• The full-frame sensor size is approximately 36X24.
• A 41 mm diameter image circle.
• The Focuser is 50.8 mm (2-inch), rack and pinion, with 10:1 dual-speed micro focuser and a 75 mm travel length. 
• A rotatable L mounting bracket.
• The tube length has a range of 230 mm when fully retracted, and 300 mm when fully extended.

William Optics ZenithStar 61II Doublet Refracting Telescope - Gray

Features

• 61 mm (2.41-inch) Aperture.
• f/5.9 Focal Ratio.
• 3.2 lb - Travel Telescope for Astrophotography and Wildlife Photography.
• Adaptable with any DSLR.
• This is the Gray Version
• Innovative Bahtinov Mask Cover for Easy Focus Assist.
• Soft Carry Case Included!

• The full-frame sensor size is approximately 36X24.
• A 41 mm diameter image circle.
• The Focuser is 50.8 mm (2-inch), rack and pinion, with 10:1 dual-speed micro focuser and a 75 mm travel length. 
• A rotatable L mounting bracket.
• The tube length has a range of 230 mm when fully retracted, and 300 mm when fully extended.

• 71mm f/4.9 Astrograph
• 350mm Focal Length
• FPL-53 glass for color-free apochromatic performance
• 4 elements in 3 groups (2-1-1- configuration; new, unique, patented design - not a conventional objective/flattener/reducer design)
• Covers 45mm full-frame imaging circle
• Precise helical focusing and camera rotation; includes a 48mm make thread that accepts a wide T-ring.
• Includes mounting rings, 21cm long Red Vixen style dovetail and Cat saddle
• Weight = 6.2lbs / 2.8kg (OTA only); 8.2lbs / 3.7kg (OTA with ring, dovetail and saddle)

• Experience our best optical performance with EdgeHD’s aplanatic, flat field Schmidt-Cassegrain optics for pinpoint stars all the way to the edge of today’s largest imaging sensors and widest eyepieces
• Aluminum optical tube with tube vents featuring an integrated 50-mesh filter allows hot air to be released from behind the primary mirror. Mirror support knobs hold the mirror in place and reduce image shift during imaging
• Versatile design accommodates 3 focal ratios: native f/10, f/7 with the addition of a focal reducer, or ultra-fast f/2 imaging with a removable secondary mirror and third-party accessories
• Celestron’s premium StarBright XLT coatings provide maximum light transmission.
• A 9x50 finderscope, 2” mirror diagonal for more comfortable viewing, and wide-angle 23 mm Luminos 2" eyepiece are all included

Bright and colorful yet smaller than a house cat, the William Optics ZenithStar 61II is one of the most portable telescopes on the William Optics market. Weighing only about 3 lb, you can easily take it with you anywhere!

• Choose Between Red, Grey, or Gold! 

Your telescope’s lens captures true-to-color light and create images with reduced chromatic aberration. It’s designed with FPL-53 glass, which is a form of synthetic fluorite in the closest form to pure fluorite. Capture mesmerizing images with brighter and crisper viewing features.

When combined with a field flattener, this telescope can capture images like those of larger professional telescopes.

Williams Optics ZenithStar 61II Special Features

• The full-frame sensor size is approximately 36X24.
• A 41 mm diameter image circle.
• The Focuser is 50.8 mm (2-inch), rack and pinion, with 10:1 dual-speed micro focuser and a 75 mm travel length. 
• A rotatable L mounting bracket.
• The tube length has a range of 230 mm when fully retracted, and 300 mm when fully extended.

Soft Carry Case Included!