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

TS Premium 80 mm f/7 ED apo refractor telescope with improved image quality due to ED objective and 2" rack & pinion focuser for astrophotography and observation

• TSED80F7: Special offer for a limited time. The telescopes are new and have full warranty.
• Premium 80 mm f/7.0 ED 2-element objective with improved chromatic correction and good light sensitivity - glas from Ohara (Japan)
• Focal length 560 mm - focal ratio f/7
• Outstanding mechanical construction with CNC tube, CNC tube rings and temperature compensated, adjustable lens mounting
• 2" dual-speed rack & pinion focuser - one of the best focusers of the TS product range for high loads
• 2" and 1.25" connection, and M54x0.75 inner thread are available for adaptations
• Very good image field correctors and also reducers for astrophotography are optionally available
• Dovetail GP/EQ5 style is included
• Finder shoe for finder scopes and small guidescopes is included

New Vixen SD103SII apochromatic high-performance refractor with FPL53 SD glass and improved optical properties for demanding observers and astrophotographers

• Apochromatic high-performance refractor with FPL53 ED glass
• Reduces chromatic aberration to an absolute minimum
• Guarantees enormously high contrast and excellent sharpness
• You get a very colour-pure, sharp and neutral image
• Very light and transportable, ideally suited for mobile applications
• Fully-coated 103 mm SD lenses without spacer plates
• No more unwanted spikes visible on the stars
• High-quality standard "Made in Japan"
• Dimensions: 115 x 810 mm
• Weight: 5.5 kg with accessories

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

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

The special feature of the 140mm SD APO with Riccardi Reducer:

• 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 with Riccardi Reducer
• CNC tube rings
• Carry handle
• Very good value for money

The Askar 203APO is one of the largest apochromatic refractors from series production - a powerful refractor for your observatory

• Aperture 203 mm - focal length 1421 mm - focal ratio f/7
• Air-spaced triplet APO objective with one ED element
• Stable 3.5" RAP focuser with speed reduction and 100 mm travel
• Working distance suitable for photo correctors and 2? accessories for observation
• Suitable for EAF motorized focus
• Two finder shoes - 1x for finder - 1x for mini guide scope

100 mm (4”) f/700 ED apochromatic refractor telescope

• Maximum useful magnification: 200x
• Aperture: 100 mm
• Focal length: 700 mm (f/7)
• Dual-speed 11:1 2" Crayford focuser
• 2.8" extension tube with scale and 360º rotation adapter
• Multi-coated lens with MHTC coating
• Slide-in dew cap
• 2" eyepiece connection
• Viewfinder shoe compatible with all Sky-Watcher viewfinders
• Tube rings with handle
• 45 mm prism rail
• Aluminium OTA with light shields
• OTA length: 570 mm (dew cap inserted), 675 mm (dew cap extended)
• OTA weight: 5.5 kg

Translated with DeepL.com (free version)

New Vixen SD115SII apochromatic high-performance refractor with FPL53 SD glass and improved optical properties for demanding observers and astrophotographers

• Apochromatic high-performance refractor with FPL53 ED glass
• Reduces chromatic aberration to an absolute minimum
• Guarantees enormously high contrast and excellent sharpness
• You get a very colour-pure, sharp and neutral image
• Very light and transportable, ideally suited for mobile applications
• Fully-coated 115 mm SD lenses without spacer plates
• No more unwanted spikes visible on the stars
• High quality standard "Made in Japan"
• Dimensions: 125 x 920 mm
• Weight: 6.3 kg with accessories

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

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

2'' Connector Takahashi FS-60/78 FC-76DC und FC-100 DC, TKA21110

• Connection (object side): M56x0,75(neg)
• Connection (observer side): 50,8mm(neg)
• lightpass: 39mm

The Askar 140APO is an apo refractor with 140 mm aperture, 980 mm focal length and a focal ratio of f/7 with many practical features.

• Aperture 140 mm - Focal length 980 mm - Focal ratio f/7
• Triplet objective with one ED element
• Stable 3.5" dual-speed RAP focuser with 360° rotation connection and 100 mm adjustment travel
• Sufficient working distance for observation with 2" accessories and for photography
• Flattener and two reducers available (0.8x)
• CNC tube rings with dovetail bar (Losmandy style) and carrying handle
• Two finder shoes

120mm (4.75”) f/900 ED Apochromatic Refractor Telescope

• 120 mm aperture, 900 mm focal length, focal ratio f/7.5
• High image quality thanks to extra-low dispersion glass FPL53 (Ohara, Japan) and matching glass from Schott
• Highly effective coating for maximum transmission and minimum reflections
• Large Crayford focuser with 11:1 reduction for sensitive focusing
• 360° rotation adapter
• Tube in traditional white - heats up less during the day and is more visible at night

Fast 70mm high-performance astrograph F5.5 for demanding astrophotographers and observers with 5 lens elements in 5 groups

• Very fast 70mm high-performance astrograph for demanding astrophotographers
• Due to the large lenses there is almost no vignetting
• Complex construction with 5 lens elements in 5 groups for absolute correction
• Needle-thin stars up to the edge of the image field even with 44 x 33 mm camera format
• Large, stable eyepiece extension, also suitable for heavy cameras
• Extremely high sharpness, colour purity and contrast thanks to SD lenses
• Very large field illumination up to 55mm
• High Strehl intensity of 96.7% at visible wavelengths
• Optional reducer available for even faster results
• Optional motor focuser with two speeds can be retrofitted

The Askar 120APO is a 120 mm aperture, 840 mm focal length, and f/7 native focal ratio apo refractor with many useful features and two corrector options.

• Aperture 120 mm - focal length 840 mm - focal ratio f/7
• Triplet objective with one ED element
• Stable 3.3" RAP focuser with dual speed, 360° rotation and 100 mm travel
• Sufficient working distance for observing with 2" accessories and for photography
• Flattener and reducer (0.8x) available
• CNC tube rings with Vixen GP style dovetail bar and carrying handle
• Two finder shoes
• With optical test by Teleskop-Service on the optical bench (autocollimation) - star test extrafocal, intrafocal and focal as well as Ronchi test and report - so you have a 100% tested telescope

The powerful ED apo is suitable for observing and astrophotography with an high-contrast image.

• 150 mm aperture, 1200 mm focal length, focal ratio f/8
• High image quality thanks to extra-low dispersion glass FPL53 (Ohara, Japan) and matching glass from Schott
• Highly effective coating for maximum transmission and minimum reflections
• Large rack and pinion focuser with 11:1 reduction for sensitive focusing
• 360° rotation adapter
• Tube in traditional white - heats up less during the day and is more visible at night

Takahashi offers rotating camera mounts for its telescopes, which are necessary because most of the company's focusers are not rotatable. However, this rotator also makes sense visually, as it allows the ZSP or other accessories to be conveniently rotated into the desired position. The quality is so high that there is no play even when the screw is loosened.

• Connection on the telescope side: M56x0.75 internal thread
• Connection on the camera side: M56x0.75 external thread
• Light path: 12.3 mm
• Weight: 110 g

The Askar 103APO is a 103 mm aperture, 700 mm focal length, and f/6.8 native focal ratio apo refractor with many useful features and several corrector options.

• Aperture 103 mm - focal length 700 mm - focal ratio f/6.8
• Triplet objective with one ED element
• Stable 3.3" RAP focuser with dual speed, 360° rotation and 100 mm travel
• Sufficient working distance for observing with 2" accessories and for photography
• Flattener and two reducers available (0.6x and 0.8x)
• CNC tube rings with Vixen/EQ5 style dovetail bar and carrying handle
• Two finder shoes

The Esprit-70EDX from Skywatcher offers the highest optical and mechanical quality and is optimized for astrophotography.

• Aperture 70 mm
• Focal length 490 mm (f/7)
• Triplet apo objective with FCD100 ED element
• Improved 2.8" dual-speed focuser for high payload
• 360° rotation
• 2" connection with additional thread for screw adaptations
• Retractable dew shield
• Carrying handle, Vixen GP style dovetail bar, carrying case