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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 UltraCat Astrographs

William Optics UltraCat astrographs are Petzval refractors in the Cat series, built for fast, flat-field deep-sky imaging without a separate flattener. The UltraCat 56, 76 and 108 work at f/4.8 and use WIFD internal focusing.

The Ultra-Cat 131 at f/4.9 is the largest in the line, for more resolution on smaller galaxies and nebulae. The small apertures suit travel rigs, while the bigger ones need a sturdier equatorial or harmonic mount.

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$3,998.00 - $3,998.00
$3,998.00
$3,998.00 - $3,998.00
$3,998.00

William Optics UltraCat 108 f/4.8 WIFD

WO-T-C-108BR
1 in stock

108mm Aperture, 5-Element Advanced Petzval Optical Design Fast f/4.8 Focal Ratio with 518mm Focal Length Massive 60mm Flat-Field Image Circle Pate...

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$3,998.00 - $3,998.00
$3,998.00
$3,998.00 - $3,998.00
$3,998.00
$1,398.00 - $1,398.00
$1,398.00
$1,398.00 - $1,398.00
$1,398.00

William Optics UltraCat 56 f/4.8 WIFD

WO-T-C-56BR
6 in stock

56mm Aperture, 269mm Focal Length (f/4.8) 5-Element Advanced Petzval Optical Design 50mm Image Circle for Full-Frame Sensors William Optics Intern...

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$1,398.00 - $1,398.00
$1,398.00
$1,398.00 - $1,398.00
$1,398.00
William Optics Ultra-Cat 131 f/4.9 Petzval Astrograph
$5,398.00 - $5,398.00
$5,398.00
$5,398.00 - $5,398.00
$5,398.00

William Optics Ultra-Cat 131 f/4.9 Petzval Astrograph

WO-T-C-131BR

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

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$5,398.00 - $5,398.00
$5,398.00
$5,398.00 - $5,398.00
$5,398.00
$2,198.00 - $2,198.00
$2,198.00
$2,198.00 - $2,198.00
$2,198.00

William Optics UltraCat 76 f/4.8 WIFD

WO-T-C-76BR
2 in stock

76 mm Aperture, 365 mm Focal Length (f/4.8) 5-Element Advanced Petzval Optical Design 50 mm Corrected Image Circle William Optics Internal Focusin...

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$2,198.00 - $2,198.00
$2,198.00
$2,198.00 - $2,198.00
$2,198.00