Optical Tubes Only (OTA)

70mm Aperture Quadruplet Astrograph 474mm Focal Length (f/6.78) 32mm Corrected Flat-Field Image Circle 2.5" Rack-and-Pinion Focuser 127.5mm Workin...

102mm Aperture ED Doublet Refractor 714mm Focal Length (f/7) S-FPL51 Extra-Low Dispersion Glass 1:10 Dual-Speed Rack & Pinion Focuser 101.9mm ...

102mm Aperture 663mm Focal Length (f/6.5) Achromatic Doublet Lens 2.5-inch Dual-Speed RAP Focuser 210mm Vixen-Style Dovetail Description FAQ Sp...

90mm Aperture 500mm Focal Length (f/5.5) Achromatic Doublet Lens 2-inch Dual-Speed Rack-and-Pinion Focuser Fully Multi-Coated (FMC) Optics Net Wei...

90mm Aperture Maksutov-Cassegrain Optical Design Internal Baffling for Stray Light Control 70mm Vixen-Style Dovetail Plate Standard 1.25-inch Focu...

105mm Maksutov-Cassegrain Optics 1365mm Focal Length f/13 Focal Ratio Weighs Only 4.83 lbs (2193g) 377mm Optical Tube Length Dual Finder Mounting ...

54mm Aperture / 243mm Focal Length (f/4.5) 5-Element Petzval APO Optical Design 44mm Full-Frame Image Circle Variable f/4.5 to f/22 Aperture Ring ...

131mm Aperture 648mm Focal Length (f/4.9) 5-Element Advanced Petzval Optical Design 60mm Flat-Field Image Circle Patented WIFD Internal Focuser 13...

310mm Aperture Aspherical Primary Mirror 1178mm Focal Length at a Fast f/3.8 55mm Corrected Image Circle for Medium Format Sensors Triplet Correct...

111mm Aperture Quadruplet APO Optics 766mm Focal Length at f/6.9 44mm Full-Frame Corrected Image Circle Integrated Field Flattener Design 5.74kg N...

131mm Aperture f/7.5 Focal Ratio Quadruplet Air-Spaced APO Optical Design Includes one ED Glass Element 44mm Full-Frame Image Circle Integrated Fi...

60mm Aperture Quadruplet APO Optics 408mm Focal Length f/6.8 Native Focal Ratio 44mm Full-Frame Image Circle Integrated Field Flattener 2.86kg Gro...

203mm Aperture Triplet Air-Spaced APO Objective 1421mm Focal Length at f/7 Includes one ED (Extra-Low Dispersion) Glass Element Retractable Tube D...

151mm Aperture Quadruplet APO Optics 1057mm Focal Length at f/7 Integrated Flattener for a 60mm Image Circle Includes Two ED Glass Elements for Co...

65mm Aperture Quintuplet APO Optical Design 416mm Focal Length at f/6.4 Built-in Field Flattener with 44mm Image Circle 2.8kg Total Weight Includi...

130mm Aperture Quintuplet Petzval APO Optics 624mm Focal Length at a Fast f/4.8 Focal Ratio 55mm Corrected Image Circle for Medium Format Sensors ...

160mm Aperture Parabolic Mirror f/3.4 Focal Ratio with Included 0.95x Corrector 544mm Corrected Focal Length Carbon Fiber Tube Construction 3.97kg...

Designed with the discerning astrophotographer in mind, Sky-Watcher’s ALL NEW top-of-the-line Esprit EDX refractors deliver the kind of imaging per...

Ouverture de 131mm Focale de 983mm (f/7.5) Formule quadruplet à 4 éléments à lame d'air Porte-oculaire à crémaillère double vitesse de 3" Poids de...

Ouverture de 90mm Focale de 609mm (f/6.8) Formule optique quadruplet à 4 éléments Porte-oculaire à crémaillère 3" double vitesse Poids de 9.97 lb ...

60mm Aperture Sextuplet APO Optics 276mm Focal Length at a Fast f/4.6 44mm Full-Frame Corrected Image Circle Integrated Petzval Design with 2 SD G...

Aperture: 127mm Focal Length: 660mm Focal Ratio: f/5.2 Optical Design: APO Nagler-Petzval (4 elements / 2 groups) Focuser: 2.4" Focusmate Dual-Spe...

Aperture: 101mm Focal Length: 540mm Focal Ratio: f/5.4 Optical Design: APO Nagler-Petzval (4 elements / 2 groups) Focuser: 2.4" Focusmate Dual-Spe...

Aperture: 85mm Focal Length: 600mm Focal Ratio: f/7 Optical Design: APO Doublet (2 elements / 1 group) Focuser: 2-inch Focusmate Dual-Speed Rack a...