Apochromatic Refractors

The new ZenithStar 61 are the most versatile and lightest apos from William Optics.

• High-quality optics with FPL53 lenses
• Universally applicable for nature and astronomical observations
• Ideal for astrophotography
• An ideal travel instrument
• Precise R&P focuser with 1:10 gear reduction

The FLT 91 is the perfect apochromatic refractor for visually and photographically observing astronomers who demand the most from a medium-sized telescope.

• Three-element design with FPL53 glass
• 91 mm aperture, 540 mm focal length
• Rack and pinion focuser with gear reduction and "Rotolock" clamp
• Field rotator with degree markings and position lock
• Prism rail according to Vixen standard
• Versatile handle with Vixen standard finder shoe
• William Optics' patented Bahtinov mask

The Gran Turismo refractor is an apochromatic triplet with FPL-53 element for highest colour purity and strong contrast! A refracting telescope that is versatile and leaves little to be desired.

• An ideal travel instrument
• High-quality 3-lens optics
• Can be used visually and photographically
• 2.5" focuser with 1:10 gear reduction
• Supplied with focus mask according to Bahtinov

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 FPL53 triplet lens with air gap
• 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

Innovative and revolutionary William Optics design combines precise internal focusing with the highest quality optics available to create the ultimate apochromatic refractor for astrophotography

• FPL53 Triplet Lens
• Aperture 81 mm, focal length 480 mm
• Internal focusing prevents image shift and vignetting
• Saddle bar handle for mounting the guiding telescope
• Incl. test report
• Incl. carrying bag

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

The special feature of the 140mm SD APO:

• Very high quality processed and of convincingly good optical quality
• Colorless optics with FLP53 glass
• Precise 2.5" focuser with 1:10 mirco reduction for heavy accessories
• With f / 7 ideal for visual
• With f/5,25 ideal for photographic purposes
• &CNC tube rings
• Carry handle
• Very good value for money

Apochromatic refractor AP 130/780 LZOS 3.7-ZTA OTA 

• Our LZOS Super ED 3-lens models come with a test report, meaning that each lens is individually measured using a Twymann interferometer and recorded with the serial number of the lens.
• Maximum Strehl ratio (as with the Zeiss APQ) is guaranteed to be 95% or better.
• Residual chromatic aberration optimized to a minimum.
• Temperature-compensating mount.

The Askar 160APO is an apo refractor with 160 mm aperture, 1120 mm focal length and a focal ratio of f/7 with many practical features.

• Aperture 160 mm - focal length 1120 mm - focal ratio f/7
• Air-spaced triplet objective with one ED element
• Stable 3.5" dual-speed RAP focuser with 360° rotator and 100 mm drawtube travel
• Sufficient working distance for observation with 2" accessories and for photography
• CNC tube rings with dovetail bar (Losmandy) and carrying handle
• Two finder shoes

• Objective Lens Diameter: 80mm
• Telescope Focal Length: 600mm (f/7.5)
• Dual-Speed 11:1 2” Crayford Focuser (Backlash-Free)
• 2.8" Indexed Focuser Drawtube with 360º Rotatable Adaptor
• Multi-Coated Objective Lens with MHTC coatings
• Image Height 30mm (with optional reducer/flattener)
• Retractable Dew Shield
• Drawtube Adaptor to accept 2" Star Diagonal
• Finderscope Mounting Shoe (compatible with ALL Sky-Watcher finderscopes)
• Supplied with Tube Rings with Carrying handle

• The SV550 122mm uses an FPL-51 triplet apochromatic lens configuration with one piece of ED glass. The triplet lens offers better correction of aberrations, significantly reduces chromatic aberrations and improves clarity and sharpness.
• The gear ratio of the dual-speed 2.5-inch rack-and-pinion focuser is 1:10, enabling precise focusing. The dual-speed focuser offers two focusing speeds via a set of coaxial knobs, for quick focusing and fine-tuning.
• The SV550 refractor is made from aluminium alloy and CNC-machined, giving it high quality for harsh environments and a longer service life.
• Compatible with 2-inch interface & M631 thread. The SV550 refractor is compatible with 2-inch and M631 accessories. At the front is a 2-inch adapter for connecting a camera or 2-inch accessories.
• The tube rings have 26 screw holes and a mounting screw handle. Tube rings with this many screw holes can be compatible with a wide range of devices, such as a smart Wi-Fi device, a guide scope, an astronomical camera, etc., to meet various installation requirements.