William Optics Ultra-Cat 76 f/4.8 WIFD Petzval Refractor Telescope
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The Ultra-Cat 76 is a high-performance 76mm apochromatic refractor, designed for astrophotographers who demand exceptional clarity and true color accuracy.
With a 5-element advanced Petzval optical design, including super ED and lanthanum glass, and a fast f/4.8 focal ratio, this telescope delivers stunningly sharp, flat-field images across its 50mm image circle. Optimized for Full Frame, APS-C, and M4/3 sensors, it also offers compatibility with Medium Format cameras for outstanding wide-field astrophotography.
Key Features:
Advanced 5-Element Petzval Optics
Eliminates field curvature, ensuring sharp, edge-to-edge stars without additional flatteners.
50mm Large Image Circle
Fully supports Full Frame cameras, APS-C and M4/3 sensors for optimal performance. Compatible with Medium Format.
Fast f/4.8 Optics
Superior light-gathering capability, enabling deep-sky imaging with shorter exposure times.
WIFD (William’s Internal Focuser Design)
Patented internal rack-and-pinion focuser ensures stable and precise focusing.
No vignetting or balance issues — ideal for astrophotography.
Compatible with EAF (Electronic Automatic Focuser) for precision focus control.
Sensor Tilt Xterminator (STX) & Rotator
Integrated tilt adjuster eliminates sensor misalignment, ensuring uniform image sharpness.
No Flattener Required
The optical design naturally corrects field curvature, simplifying setup.
Anti-Shrink Lens Cell Technology
Reduces thermal expansion effects, maintaining perfect optical alignment in any climate.
Patented Bahtinov Mask for Focusing
Built-in focusing aid ensures pinpoint star sharpness with ease.
Premium Build & Ergonomic Design
Lightweight yet robust (4.31 kg / 9.5 lbs) construction with a sleek anodized finish.
Patented handle bar design for enhanced portability and ease of use.
Versatile Camera Compatibility
Supports Canon EF, RF, Nikon F,Z, Sony E, Pentax K, MFT, and FUJI X mounts.
Specifications:
- Lens Type: 5-Element Advanced Petzval
- Lens Elements:
- Super ED Glass x2
- ED Glass x1
- Lanthanum Glass x1
- X-Element x1
- Focal Length: 365 mm
- Diameter:
- 76 mm
- Focal Ratio
- f/4.8
- Image circle: 50 mm
- Focuser: WIFD R&P Focuser, Compatible with EAF
- Focus travel: 0-20 mm (Ruler to 21mm)
- Adapter Included:
- Sensor Tilt Xterminator
- Rotator
- M54, M48 Camera Adapters
- Optional Flattener: No Flattener Required
- T-Mount Support:
- Canon EF, RF
- Nikon F, Z
- Sony E
- Pentax K
- MFT (M4/3)
- FUJI X
- Camera Format:
- Medium Format (Compatible)
- Full Frame (Recommended)
- APS-C
- M4/3
- Dovetail Type: Vixen ↔︎ Arca-Swiss
- Tube Length: 363 mm - 415 mm
- OTA Weight: 3.81 kg / 8.4 lbs
- Total Weight: 4.98 kg / 10.98 lbs
Other Information
- Country of Manufacture: Taiwan
The Ultra-Cat 76 is a high-performance 76mm apochromatic refractor, designed for astrophotographers who demand exceptional clarity and true color accuracy.
With a 5-element advanced Petzval optical design, including super ED and lanthanum glass, and a fast f/4.8 focal ratio, this telescope delivers stunningly sharp, flat-field images across its 50mm image circle. Optimized for Full Frame, APS-C, and M4/3 sensors, it also offers compatibility with Medium Format cameras for outstanding wide-field astrophotography.
Key Features:
Advanced 5-Element Petzval Optics
Eliminates field curvature, ensuring sharp, edge-to-edge stars without additional flatteners.
50mm Large Image Circle
Fully supports Full Frame cameras, APS-C and M4/3 sensors for optimal performance. Compatible with Medium Format.
Fast f/4.8 Optics
Superior light-gathering capability, enabling deep-sky imaging with shorter exposure times.
WIFD (William’s Internal Focuser Design)
Patented internal rack-and-pinion focuser ensures stable and precise focusing.
No vignetting or balance issues — ideal for astrophotography.
Compatible with EAF (Electronic Automatic Focuser) for precision focus control.
Sensor Tilt Xterminator (STX) & Rotator
Integrated tilt adjuster eliminates sensor misalignment, ensuring uniform image sharpness.
No Flattener Required
The optical design naturally corrects field curvature, simplifying setup.
Anti-Shrink Lens Cell Technology
Reduces thermal expansion effects, maintaining perfect optical alignment in any climate.
Patented Bahtinov Mask for Focusing
Built-in focusing aid ensures pinpoint star sharpness with ease.
Premium Build & Ergonomic Design
Lightweight yet robust (4.31 kg / 9.5 lbs) construction with a sleek anodized finish.
Patented handle bar design for enhanced portability and ease of use.
Versatile Camera Compatibility
Supports Canon EF, RF, Nikon F,Z, Sony E, Pentax K, MFT, and FUJI X mounts.
Specifications:
- Lens Type: 5-Element Advanced Petzval
- Lens Elements:
- Super ED Glass x2
- ED Glass x1
- Lanthanum Glass x1
- X-Element x1
- Focal Length: 365 mm
- Diameter:
- 76 mm
- Focal Ratio
- f/4.8
- Image circle: 50 mm
- Focuser: WIFD R&P Focuser, Compatible with EAF
- Focus travel: 0-20 mm (Ruler to 21mm)
- Adapter Included:
- Sensor Tilt Xterminator
- Rotator
- M54, M48 Camera Adapters
- Optional Flattener: No Flattener Required
- T-Mount Support:
- Canon EF, RF
- Nikon F, Z
- Sony E
- Pentax K
- MFT (M4/3)
- FUJI X
- Camera Format:
- Medium Format (Compatible)
- Full Frame (Recommended)
- APS-C
- M4/3
- Dovetail Type: Vixen ↔︎ Arca-Swiss
- Tube Length: 363 mm - 415 mm
- OTA Weight: 3.81 kg / 8.4 lbs
- Total Weight: 4.98 kg / 10.98 lbs
| Manufacturer | William Optics |
|---|---|
| Telescope Focal Length | 301 - 400mm |
The Ultra-Cat 76 is a high-performance 76mm apochromatic refractor, designed for astrophotographers who demand exceptional clarity and true color accuracy.
With a 5-element advanced Petzval optical design, including super ED and lanthanum glass, and a fast f/4.8 focal ratio, this telescope delivers stunningly sharp, flat-field images across its 50mm image circle. Optimized for Full Frame, APS-C, and M4/3 sensors, it also offers compatibility with Medium Format cameras for outstanding wide-field astrophotography.
Key Features:
Advanced 5-Element Petzval Optics
Eliminates field curvature, ensuring sharp, edge-to-edge stars without additional flatteners.
50mm Large Image Circle
Fully supports Full Frame cameras, APS-C and M4/3 sensors for optimal performance. Compatible with Medium Format.
Fast f/4.8 Optics
Superior light-gathering capability, enabling deep-sky imaging with shorter exposure times.
WIFD (William’s Internal Focuser Design)
Patented internal rack-and-pinion focuser ensures stable and precise focusing.
No vignetting or balance issues — ideal for astrophotography.
Compatible with EAF (Electronic Automatic Focuser) for precision focus control.
Sensor Tilt Xterminator (STX) & Rotator
Integrated tilt adjuster eliminates sensor misalignment, ensuring uniform image sharpness.
No Flattener Required
The optical design naturally corrects field curvature, simplifying setup.
Anti-Shrink Lens Cell Technology
Reduces thermal expansion effects, maintaining perfect optical alignment in any climate.
Patented Bahtinov Mask for Focusing
Built-in focusing aid ensures pinpoint star sharpness with ease.
Premium Build & Ergonomic Design
Lightweight yet robust (4.31 kg / 9.5 lbs) construction with a sleek anodized finish.
Patented handle bar design for enhanced portability and ease of use.
Versatile Camera Compatibility
Supports Canon EF, RF, Nikon F,Z, Sony E, Pentax K, MFT, and FUJI X mounts.
Specifications:
- Lens Type: 5-Element Advanced Petzval
- Lens Elements:
- Super ED Glass x2
- ED Glass x1
- Lanthanum Glass x1
- X-Element x1
- Focal Length: 365 mm
- Diameter:
- 76 mm
- Focal Ratio
- f/4.8
- Image circle: 50 mm
- Focuser: WIFD R&P Focuser, Compatible with EAF
- Focus travel: 0-20 mm (Ruler to 21mm)
- Adapter Included:
- Sensor Tilt Xterminator
- Rotator
- M54, M48 Camera Adapters
- Optional Flattener: No Flattener Required
- T-Mount Support:
- Canon EF, RF
- Nikon F, Z
- Sony E
- Pentax K
- MFT (M4/3)
- FUJI X
- Camera Format:
- Medium Format (Compatible)
- Full Frame (Recommended)
- APS-C
- M4/3
- Dovetail Type: Vixen ↔︎ Arca-Swiss
- Tube Length: 363 mm - 415 mm
- OTA Weight: 3.81 kg / 8.4 lbs
- Total Weight: 4.98 kg / 10.98 lbs
Other Information
- Country of Manufacture: Taiwan
| Manufacturer | William Optics |
|---|---|
| Telescope Focal Length | 301 - 400mm |
William Optics Ultra-Cat 76 f/4.8 WIFD Petzval Refractor Telescope