List of products by brand William Optics

William Optics Apochromatic refractor AP 71/350 RedCat 71 WIFD OTA (83232)
1757.29 €
Tax included
The AP 71/350 offers a remarkable balance of compact size, affordability, and superior optical quality, making it an excellent choice for both astronomy and nature photography. Its optical system is based on a Petzval design with 4 elements in three groups, utilizing FPL53 and FPL51 glass. This setup delivers a richly colored, fully corrected image field with a diameter exceeding 45 millimeters—ideal for full-frame cameras!
William Optics Apochromatic refractor AP 51/178 MiniCat WIFD OTA (84908)
954.87 €
Tax included
The Cat series astrographs, available in the RedCat and SpaceCat color variants, are designed for simplicity and high performance in nature observation and astrophotography. At the core of these optics lies a Petzval design, featuring four lenses in three elements. This design provides a color-corrected and flat field of view without the need for an external field flattener. Unique features include a field rotator with an integrated filter holder, enabling seamless camera rotation, and a tilting collimator to achieve precise alignment of the image plane with the camera sensor.
William Optics Apochromatic refractor AP 51/250 RedCat WIFD OTA (82930)
881.85 €
Tax included
The AP 51/250 is a remarkable optic that combines compact size, affordability, and outstanding optical quality—perfect for astrophotographers and nature photographers alike. At its core is a Petzval optical design, featuring four elements in three groups, made from high-grade FPL53 and FPL51 glass. This results in a color-true, well-corrected image circle over 44mm in diameter—making it ideal for full-frame cameras! Its fast f/4.9 aperture enables short exposure times.
William Optics Apochromatic refractor AP 91/448 BlackCat 91 WIFD OTA (85223)
2647.18 €
Tax included
The AP 91/448 is an outstanding optical instrument that combines a compact form, attractive price, and excellent optical performance—perfect for both astrophotographers and nature photographers. Its heart is a Petzval design featuring four elements in three groups, made from premium FPL53 and FPL51 glass. This configuration produces a color-accurate, well-corrected image field with a diameter of over 55mm, making it ideal for full-frame cameras. Its fast f/4.9 aperture enables short exposure times.
William Optics Apochromatic refractor AP 91/448 RedCat 91 WIFD OTA (85222)
2647.18 €
Tax included
The AP 91/448 is a remarkable optical instrument, blending compact size, competitive price, and exceptional image quality—ideal for both astrophotographers and nature photographers. At its core is a Petzval optical design with four elements in three groups, utilizing premium FPL53 and FPL51 glass. This setup provides a color-accurate, well-corrected image circle over 55mm in diameter, perfect for full-frame cameras. The fast f/4.9 aperture enables short exposure times for sharp, detailed images.
William Optics Apochromatic refractor AP 132/925 Fluorostar Gold OTA (65801)
4653.22 €
Tax included
The Fluorostar features a triplet objective lens design with air gaps, crafted from premium FPL-53 ED glass by Ohara, Japan, combined with lanthanum elements. This exceptional construction guarantees outstanding color fidelity and crystal-clear images—making the Fluorostar a truly high-end instrument. Pair this apochromat with a high-quality William Optics star diagonal, and you’ll experience stellar views rarely matched by other telescopes. 
William Optics Apochromatic refractor AP 132/925 FluoroStar Red OTA (75400)
4565.76 €
Tax included
The FluoroStar features a premium objective lens made up of three air-spaced elements, including special FPL-53 ED glass from Ohara, Japan, and lanthanum glass. This advanced triplet design ensures exceptional color correction and crystal-clear views, making this telescope a true high-end instrument for demanding astronomers. Pair this apochromatic refractor with a top-quality diagonal from William Optics and you’ll enjoy star views of remarkable sharpness rarely matched by other telescopes. 
William Optics Apochromatic refractor AP 156/1217 Fluorostar Gray OTA (85097)
7534.71 €
Tax included
The FluoroStar features a top-tier objective lens comprised of three air-spaced elements, utilizing premium FPL-53 ED glass from Ohara, Japan, combined with lanthanum glass. This sophisticated triplet design ensures outstanding color fidelity and image clarity, making it a true high-end instrument. Pair this apochromat with a high-quality William Optics diagonal, and you’ll experience star views of exceptional sharpness that few telescopes can match. 
William Optics Apochromatic refractor AP Fluorostar 120/780 Gold OTA (74017)
3843.59 €
Tax included
The FluoroStar’s objective lens features a premium air-spaced triplet design, using FPL-53 ED glass from Ohara, Japan, combined with lanthanum glass elements. This exceptionally high-quality optical system delivers outstanding color fidelity and sharpness—making it a truly top-tier instrument. Pair this apochromatic refractor with a quality diagonal from William Optics, and you’ll enjoy stargazing with a level of clarity that few telescopes can match. 
William Optics Apochromatic refractor AP Fluorostar 120/780 Space Gray OTA (74018)
3843.59 €
Tax included
The FluoroStar’s objective lens is a high-end, air-spaced triplet featuring premium FPL-53 ED glass from Ohara, Japan, combined with lanthanum elements. This advanced optical design ensures excellent color fidelity and image clarity, meeting the highest standards for serious astronomers. Pair this apochromatic refractor with a quality diagonal from William Optics, and you’ll experience star views with a sharpness and detail rarely matched by other telescopes. 
William Optics Apochromatic refractor AP 71/420 Gran Turismo GT 71 OTA (75650)
954.87 €
Tax included
The Gran Turismo refractor is an apochromatic triplet telescope with an FPL-53 element, delivering outstanding color correction and high contrast. This versatile scope is designed to meet the needs of demanding observers and astrophotographers alike. When paired with an optional diagonal, the GT 71 offers stunning, high-contrast views of the Moon and planets. Its fast optics also allow you to enjoy deep sky objects—such as star clusters, galaxies, and nebulae—with crisp, pinpoint stars, making globular cluster observation and analysis especially enjoyable.
William Optics Apochromatic refractor AP 81/478 GranTurismo 81WIFD OTA (77771)
1604.03 €
Tax included
William Optics’ GranTurismo refractors are renowned for their FPL-53 glass, offering exceptional color accuracy and high contrast. This versatile apochromatic refractor meets the demands of both visual astronomers and astrophotographers. With an optional diagonal mirror, the GT81 provides high-contrast views of the Moon and planets. Its fast optics allow for extended observation of challenging deep-sky objects—star clusters, galaxies, and nebulae—all with crisp, pinpoint stars, making globular cluster observation especially rewarding.
William Optics Apochromatic refractor AP 108/518 UltraCat WIFD (86137)
3104.09 €
Tax included
The William Optics UltraCat108 is a state-of-the-art 108mm apochromatic refractor crafted for astrophotographers who require the highest level of optical performance. With its sophisticated 5-element Petzval design and a fast f/4.8 focal ratio, the UltraCat108 delivers stunning, edge-to-edge clarity and vibrant detail, making it ideal for capturing wide, breathtaking views of the night sky. Its solid construction, exceptional optics, and unique features set a new standard in astrophotography telescopes.
William Optics 40mm SWAN eyepiece, 2'' (4723)
152.5 €
Tax included
The SWAN eyepiece delivers reference-quality performance at an outstanding price. With its fully multi-coated lenses and advanced optical design, it offers a super wide 72° apparent field of view, creating an immersive experience much like looking out of a spaceship window. The "Moon Walk" effect is achieved to perfection, making lunar and deep sky observing truly impressive.
William Optics 1,25'' 45° Amici prism on 1,25'' (4712)
112.75 €
Tax included
This 1.25'', 45° erecting prism (Amici prism) from William Optics is compatible with any 1.25'' eyepiece or telescope with a 1.25'' focuser. It produces images that are upright and correctly oriented left-to-right. Offering both high quality and affordability, this Amici prism sets a new standard for image-correcting prisms.