Skip to content

William Optics Zenithstar APO Refractors

William Optics Zenithstar refractors are compact apochromatic doublets for portable astrophotography and visual observing. This collection includes the Zenithstar 61II APO, a small travel scope, and the Zenithstar 81 WIFD with internal focusing.

Dedicated correctors are also here: the adjustable Flat61 flattener and Flat61R reducer flattener for the Z61, and the Flat73A flattener and Flat73R reducer flattener for the Z73, which let you choose between native and reduced focal length.

Filters

CA$384.00 - CA$384.00
CA$384.00
CA$384.00 - CA$384.00
CA$384.00

William Optics Adjustable Flat73A for Z73

WO-P-FLAT73A
1 in stock

Designed specifically for the William Optics ZenithStar 73 APO Delivers a 1.0x, perfectly flat field across full-frame sensors Connects to the Z73...

View full details
CA$384.00 - CA$384.00
CA$384.00
CA$384.00 - CA$384.00
CA$384.00
CA$962.00 - CA$962.00
CA$962.00
CA$962.00 - CA$962.00
CA$962.00

William Optics Zenithstar 61II APO

Options available

61mm Aperture Apochromatic Doublet Refractor Ohara FPL-53 ED Glass Element Fast f/5.9 Focal Ratio for Wide-Field Imaging Includes Flat61A Field Fl...

View full details
CA$962.00 - CA$962.00
CA$962.00
CA$962.00 - CA$962.00
CA$962.00
CA$384.00 - CA$384.00
CA$384.00
CA$384.00 - CA$384.00
CA$384.00

William Optics Adjustable Flat61 for Z61

WO-P-FLAT61A
1 in stock

1.0x Flattener Power Designed for William Optics Zenithstar 61 Full-Frame Sensor Coverage Adjustable Back Focus Mechanism M54 Telescope Thread &am...

View full details
CA$384.00 - CA$384.00
CA$384.00
CA$384.00 - CA$384.00
CA$384.00
CA$1,398.00 - CA$1,515.00
CA$1,398.00 - CA$1,515.00
CA$1,398.00 - CA$1,515.00
CA$1,398.00

William Optics Zenithstar 81 WIFD Telescope

Options available

Patented William Optics Internal Focus Design (WIFD) Rigid M92 Rear Thread with M63 Adapter Included Vixen/Arca-Swiss Dual-Sided Mounting Plate In...

View full details
CA$1,398.00 - CA$1,515.00
CA$1,398.00 - CA$1,515.00
CA$1,398.00 - CA$1,515.00
CA$1,398.00
CA$409.00 - CA$409.00
CA$409.00
CA$409.00 - CA$409.00
CA$409.00

William Optics Adjustable Reducer Flattener Flat61R for Z61

WO-P-FLAT61R

Adjustable reducer and field flattener for William Optics Z61 telescope Improves image sharpness and reduces distortion Description ...

View full details
CA$409.00 - CA$409.00
CA$409.00
CA$409.00 - CA$409.00
CA$409.00
CA$409.00 - CA$409.00
CA$409.00
CA$409.00 - CA$409.00
CA$409.00

William Optics Adjustable Reducer Flattener Flat73R for Z73

WO-P-FLAT73R

Reduces focal length by a factor of 0.8x Designed for the William Optics Zenithstar 73 telescope Provides edge-to-edge flat field for full-frame s...

View full details
CA$409.00 - CA$409.00
CA$409.00
CA$409.00 - CA$409.00
CA$409.00