William Optics Apochromatic refractor AP 132/925 FluoroStar Red OTA (75400)

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. Double stars split cleanly, Jupiter’s bands and zones show impressive detail, and Saturn’s rings appear as if seen from a spaceship.

Thanks to its large aperture and unobstructed light path (with no secondary mirrors like those in reflectors), the FluoroStar opens up the world of Messier objects and deep-sky targets. Once you experience the stunning clarity of a high-quality apochromat, you’ll never want to look away from the universe!

For astrophotographers, the FluoroStar’s large image circle delivers bright, even illumination across the field, perfect for full-frame cameras. When combined with the William Optics Flat7A field flattener, it achieves a fast f/5.6 focal ratio. The flattener attaches securely to the focuser for reliable imaging performance.

The focuser offers smooth and precise micro-adjustment, an integrated temperature gauge, and a wide adjustment range. It easily supports heavy astrophotography gear and allows for full rotation to help you frame your shot perfectly on the camera sensor.

A unique feature of the latest William Optics apochromats is the specially designed Bahtinov focus mask, made from optical acrylic glass with 92% transparency. The engraved pattern creates a diffraction pattern about three times brighter than standard metal masks, allowing you to achieve sharp focus even on fainter stars.

Specifications

Optics

• Type: Refractor (Apochromat, Triplet lens)

• Aperture: 132 mm

• Focal Length: 925 mm

• Focal Ratio: f/6.9

• Resolving Power: 1.05 arcseconds

• Limiting Magnitude: 12.4

• Light Gathering Power: 360× the naked eye

• Maximum Magnification: 264×

Mechanical

• Tube Weight: 9 kg

• Tube Diameter: 141 mm

• Tube Length: 1040 mm

• Carrying Length: 780 mm

• Coating: STM

Focuser

• Type: Rack and pinion, rotatable

• Eyepiece Connection: 2"

• Camera Thread: T2

• Clear Aperture: 84 mm

• Gear Reduction: 1:10 fine focusing

• Travel Range: 95 mm

• Telescope-Side Thread: 3.7"

Mount

• Type: OTA (Optical Tube Assembly; no mount included)

Included Accessories

• Prism Rail: Losmandy-style

• Carrying Handle: Yes

• Focus Aid: Bahtinov focus mask

• Carry Case: Yes

• Finder Base: Vixen/Skywatcher standard

• Deviating Optics (Diagonal): Not included

General

• Series: FluoroStar

• Color: Red

Recommended Use

• Astrophotography: Yes (excellent)

• Moon & Planets: Yes

• Nature Observation: No

• Nebulae & Galaxies: Yes

• Solar Observation: No (only with suitable solar filter)

User Level

• Beginners: No

• Advanced Users: Yes

• Observatories: Yes