Skip to content
IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.

William Optics Field Flatteners, Reducers & Coma Correctors

William Optics field flatteners and reducers correct field curvature so stars stay round to the edge of the sensor, and the reducers also shorten the focal length for faster exposures. Several are adjustable, so the spacing can be tuned for different telescopes.

The range includes the Flat61 and Flat61R for the Z61, the Flat73A and Flat73R for the Z73, the Flat6AIII, the Flattener 68III, the 0.8x Reducer Flattener 7A, the 0.72x Reducer Flattener 8 and the Ultra Flat 132 and 156 0.79x reducers.

Filters

$269.00 - $269.00
$269.00
$269.00 - $269.00
$269.00

William Optics Adjustable Flat6AIII

WO-P-FLAT6AIII
2 in stock

0.8x Focal Reducer & Field Flattener Optimized for GT71, GT81, Z81 & Z103 Refractors Illuminates Full-Frame Sensors Adjustable Back Focus ...

View full details
$269.00 - $269.00
$269.00
$269.00 - $269.00
$269.00
$278.00 - $278.00
$278.00
$278.00 - $278.00
$278.00

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
$278.00 - $278.00
$278.00
$278.00 - $278.00
$278.00
$348.00 - $348.00
$348.00
$348.00 - $348.00
$348.00

William Optics Adjustable Flat6AIII for FLT91

WO-P-FLAT6AIII-M92

Dedicated Field Flattener for the William Optics FLT91 Telescope Corrects Field Curvature for Pinpoint Stars Edge-to-Edge Integrated Adjustment Ri...

View full details
$348.00 - $348.00
$348.00
$348.00 - $348.00
$348.00
$278.00 - $278.00
$278.00
$278.00 - $278.00
$278.00

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
$278.00 - $278.00
$278.00
$278.00 - $278.00
$278.00
$788.00 - $788.00
$788.00
$788.00 - $788.00
$788.00

William Optics Flattener 68III

WO-P-FLAT68III

1.0x Flattener Power preserves native focal length Corrects field curvature for Full Frame sensors Designed for William Optics FLT132, GT102, and ...

View full details
$788.00 - $788.00
$788.00
$788.00 - $788.00
$788.00
$788.00 - $788.00
$788.00
$788.00 - $788.00
$788.00

William Optics x0.8 Reducer Flattener 7A

WO-P-FLAT7A

Reduces focal ratio by a factor of 0.8x Triplet lens design with 3 elements in 3 groups Corrects field curvature for full-frame sensors Designed f...

View full details
$788.00 - $788.00
$788.00
$788.00 - $788.00
$788.00
$284.00 - $284.00
$284.00
$284.00 - $284.00
$284.00

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
$284.00 - $284.00
$284.00
$284.00 - $284.00
$284.00
$284.00 - $284.00
$284.00
$284.00 - $284.00
$284.00

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
$284.00 - $284.00
$284.00
$284.00 - $284.00
$284.00
$806.00 - $806.00
$806.00
$806.00 - $806.00
$806.00

William Optics WO x0.72 Reducer Flattener 8

WO-P-FLAT8

Reduces focal ratio by a factor of 0.72x Corrects field curvature for full-frame sensors 3-element, 3-group optical design Connects to telescope v...

View full details
$806.00 - $806.00
$806.00
$806.00 - $806.00
$806.00
William Optics Ultra Flat 156 (0.79x Reducer)
$1,068.00 - $1,068.00
$1,068.00
$1,068.00 - $1,068.00
$1,068.00

William Optics Ultra Flat 156 (0.79x Reducer)

WO-P-FLAT-156

Reduces focal ratio by a factor of 0.79x Designed for Medium Format, Full Frame, and APS-C sensors 3-element, 3-group optical design Requires 75.5...

View full details
$1,068.00 - $1,068.00
$1,068.00
$1,068.00 - $1,068.00
$1,068.00
William Optics Ultra Flat 132 (0.79x Reducer)
$1,068.00 - $1,068.00
$1,068.00
$1,068.00 - $1,068.00
$1,068.00

William Optics Ultra Flat 132 (0.79x Reducer)

WO-P-FLAT-132

Reduces focal ratio by a factor of 0.79x Provides a flat field for Full Frame, APS-C, and M4/3 sensors 3-element, 3-group optical design Connects ...

View full details
$1,068.00 - $1,068.00
$1,068.00
$1,068.00 - $1,068.00
$1,068.00