William Optics Apochromates

The various apochromats from William Optics USA are very popular in the astro community. The manufacturer offers innovative ideas and a large selection of different apochromatic designs that can be universally equipped.

View as Grid List
Sort by
Display
Superior optics for stunning images

The Zenithstar 73 III APO is an apochromatic refractor telescope that impresses with excellent color correction and sharpness. Using high-quality optics, chromatic aberrations are effectively minimized, so you get clear, high-contrast, true-color images.

  • Dual element design with FPL53 glass
  • Massive 2.5" R&P focuser
  • CNC machined ALU tube
  • High quality tube clamps and mounting plate
  • Integrated handle
999.00 € 949.05 €
Estimated delivery time : 1 week (valid for new orders)
 
 
The William Optics ZenithStar 81 mm aperture Doublet APO Refactor is an extremely versatile telescope ideal for both astrophotography and general photography. 

  • Two element APO design with FPL53 glass
  •  Massive 2.5" R&P extension with 1/10 gear reduction
  •  High quality CNC machined ALU tube
  •  With tube clamps, mounting handle and mounting plate
1490.00 € 1415.50 €
Estimated delivery time : on request (valid for new orders)
 
 

William offers with the RedCat 71 WIFD astrograph a very well corrected telescope for astrophotography up to full frame format.

  • Aperture 71 mm / Focal length 350 mm / Focal ratio f/4.9
  • Petzval design with chromatic aberration free FPL53 objective (4 elements in 3 groups)
  • Very well corrected and illuminated image field up to full frame format - the corrector is built in - no more adapter battle necessary
  • Camera connection via M48 male thread (suitable adapters are available) - working distance 55 mm
  • 360° rotation of the camera for the right display window
  • Focusing via internal focusing (William Internal Focus Design - WIFD) as with telephoto lenses
  • Tilting option for individual adjustment of the camera sensor to the telescope
  • Flexible dovetail bar at the base (long version), suitable for Vixen style and Arca-Swiss saddle plates, in addition with 1/4" female photo tripod thread
  • Nylon carrying bag and Bahtinov mask for astrophotography are included in delivery
  • WIFD R&P focuser - copatible with EAF
1490.00 € 1415.50 €
Estimated delivery time : 1-4 days (valid for new orders)
 
 

The Ultra-Cat 56 is a high-performance 56 mm apochromatic refractor, designed for astrophotographers who demand exceptional clarity and true color accuracy.

  • Aperture 56 mm, focal length 269 mm
  • Focal ratio f/4.8
  • Optical design according to Petzval with integrated corrector (five elements in total)
  • No flattener necessary
  • Temperature-stable lens cells
  • Clear and sharp image even when using a full frame sensor
  • William Optics Internal Focus Design (WIFD)
  • 30 mm focuser travel
  • Rotator and tilt flange included
  • Patented multifunctional handle
  • Connection on camera side: M54, M48
1398.00 €
Estimated delivery time : 1-4 weeks (valid for new orders)
 
 

The William Optics GT 71 Apo stands for optimal color correction and best possible contrast - a powerful travel telescope for observation and photography.

  • Aperture 71 mm
  • Focal length 420 mm
  • Focal ratio f/5.9
  • Multicoated air-spaced FPL53 triplet lens
  • 2.5" RAP focuser with M63x1 connection thread, as well as 2" and 1.25"
  • Multifunction handle with holder for guide scopes
  • Bahtinov mask integrated
  • Variable carrier bag
  • Vixen/EQ5 style dovetail bar
  • Golden Edition
1190.00 € 1130.50 €
Estimated delivery time : 1-4 weeks (valid for new orders)
 
 

The Ultra-Cat 76 is a powerful apochromatic 76 mm refractor designed for astrophotographers who demand very high sharpness and color fidelity.

  • Aperture ratio 1:4.8
  • Petzval optical design with integrated corrector (five elements in total)
  • Temperature-stable lens cells
  • Color-pure and sharp imaging even when using a full-frame sensor
  • William Optics Internal Focus Design (WIFD)
  • Rotator and tilt flange included
  • Patented multifunctional handle
  • Camera-side connection: M54, M48
2290.00 €
Estimated delivery time : 1-4 weeks (valid for new orders)
 
 

The William Optics GT 81 apo stands for optimal chromatic correction and best possible contrast - a powerful travel telescope for observation and photography.

  • Aperture 81 mm
  • Focal length 480 mm
  • Focal ratio f/5.9
  • Multicoated, air-spaced FPL53 triplet lens
  • 2.5" RAP focuser with M63x1 connection thread, as well as 2" and 1.25"
  • Multifunction handle with holder for guide scopes
  • Bahtinov mask integrated
  • Variable carrier bag
  • Vixen/EQ5 style dovetail bar
1790.00 € 1700.50 €
Estimated delivery time : 1-4 days (valid for new orders)
 
 
The William Optics Ultra-Cat 131 · 30th Anniversary Limited Edition is an instrument for those who not only want to observe, but also want to hold history in their hands. This anniversary model combines the technical maturity of three decades of William Optics development with an aesthetic that will make collectors' hearts beat faster. The combination of a five-element Petzval design, Super ED glass and precise mechanical workmanship makes it one of the most powerful compact astrographs in its class
6608.00 € 6277.60 €
Estimated delivery time : 3-4 weeks (valid for new orders)
 
 
The William Optics Ultra-Cat 131 · 30th Anniversary Limited Edition is an instrument for those who not only want to observe, but also want to hold history in their hands. This anniversary model combines the technical maturity of three decades of William Optics development with an aesthetic that will make collectors' hearts beat faster. The matching ZWO AM7 Parallactic Harmonic Drive GoTo mount with pier is also available.
13590.00 € 12910.50 €
Estimated delivery time : 3-4 weeks (valid for new orders)