From the high-end Petzval lens on the optical tube assembly to the precise strain-wave gearing of the mount, the William Optics Cat 51 WIFD f/4.9 Apochromatic Telescope with ZWO AM5N Mount Kit from B&H will help you capture brilliant images of the night sky. The telescope features an innovative center-of-tube focus mechanism and creates an image circle large enough for full-frame camera sensors, while the sturdy, compact mount effortlessly moves the scope to track your subject throughout the exposure. This kit includes the OTA and the mount; you'll only need to supply a tripod.
William Optics Cat 51 WIFD 51mm f/4.9 Apochromatic Refractor Telescope (OTA Only)
Designed for stargazing and astrophotography, the Cat 51 WIFD 51mm f/4.9 Apochromatic Refractor Telescope from William Optics uses an unorthodox design for supporting heavy cameras and delivers a wide field, a fast focal ratio, and a Petzval lens for beautiful images. The WIFD (William Optic Internal Focus Design) places the 10:1 rack-and-pinion focuser in the center of the optical tube, eliminating the tilt and vignetting that can occur from heavy cameras on traditional rear-mounted focusers. A four-element Petzval-style lens yields a sharp image with no need for a flattener and the dust cover has a built-in Bahtinov mask for tack-sharp star images. This optical tube assembly requires a mount and a tripod for use.
Optical Tube Assembly
- Fast f/4.9 focal ratio and 250mm focal length for wide field of view and fast exposure times
- Apochromatic Petzval-style four-element lens produces rich views with minimal chromatic aberration
- Sharp image with no need for a separate field flattener
- Supports 48mm image circle for full-frame, APS-C, and micro four thirds cameras
- Dust cover with integrated Bahtinov mask allows for fine focusing on stars
- Built-in tilt adapter
- Camera angle rotation device
- M54 female thread for cameras, accessories, or eyepiece diagonals
Focuser
- William Optics Internal Focus Design places focuser in center of OTA to balance the weight of imaging systems
- Precise internal sliding of fixed optics prevents image shift, ensuring stable and clear observations
- 10:1 coarse and fine focus rack-and-pinion design
- Compatible with ZWO EAF automatic focuser
- 0-23mm focus travel, ruler to 30mm
Dial-style thermometer for gauging temperature effect on optical tube
Use and Handling
- Anodized aluminum optical tube
- Sturdy mounting ring and handle assembly with 210mm Vixen-style dovetail
- Additional dovetail with thumbscrews on handle for guidescope or other accessory
ZWO AM5N Harmonic Equatorial GoTo Mount
Designed with a strain wave gear reducer and synchronous belt for precise control, the ZWO AM5N Harmonic Equatorial GoTo Mount offers alt-az operation for observation and go-to equatorial tracking for astrophotography via a smartphone app or an ergonomic hand controller. The mount weighs just 12.1 pounds but can support payloads up to 33 pounds on its own or 44 pounds with a user-supplied counterweight and shaft. A brake system ensures the mount won't topple in the event of a power failure. The mount runs on a user-supplied 12V, 5A power supply and is compatible with ASCOM and ZWO's ASIAIR platforms.
Low Weight, High Payload
- Weighs 12.1 lb
- Supports 33 lb without counterweight
- Payload increases to 44 lb with optional 11 lb counterweight
- 3/8"-16 tripod mount
Strain-Wave Gear for Precision Control
- Strain-wave gearing system comes with very low ±10" periodic errors, smooth gearing, and high torque
- Reduction ratio is 300:1
- Each mount is tested and shipped with a periodic error curve report
Dual AZ/EQ Modes
- Capable of both equatorial and alt-azimuth modes
- Suitable for both visual and imaging
- Elevation angle of 0-90°
- Can be used anywhere from the equator to the polar regions
Mode Indication
- Red light is displayed for equatorial mount mode
- Green light is displayed for alt-azimuth mode
- If the mount has no synchronization, the indicator light flashes alternately red and green, and the corresponding color indicator light will be displayed according to the mode after synchronization
Joystick Handset or App Control
- Control via the included hand controller or from your phone or tablet using the AM5 app
- App offers an onscreen joystick combined with convenient tools including Best Objects of the Evening, a built-in star map with real-time display and GOTO functions
- There is no need to connect to a computer—the mount and hand controller connect via Wi-Fi
- The mount is compatible with ASCOM, INDI, ASIAIR, and other platforms
Power-Off Braking
- In the event of power failure, brakes are instantly applied to prevent the telescope and equipment from falling and resulting in damage or injury
Ports for Cable Management
- 12 VDC input and USB-C ports on saddle reduce cable tangling
- 12 VDC output supplied from the main body power socket, this outlet can share power with devices such as ASIAIR
- The mount is powered by a user-provided 12V, 5A power supply
Key Features
- 250mm Focal Length, f/4.9 Focal Ratio
- Center-Balanced Internal Focus Design
- For Full-Frame, APS-C, Micro 4/3 Cameras
- Strain-Wave Motorized Mount
- Control by App or Hand Unit
- EQ & Alt-Az Modes
- Precise 300:1 Reduction Ratio
- Supports 33 lb Without Counterweight
- Bahtinov Cap
- M48 Cap
- Mounting Ring with Handle
- Dual Mounting Plate
- Mounting Ring Handle Bar
- Allen Key Set
- Soft Carry Case
- Limited 2-Year Manufacturer Warranty
| Key Specs | |
|---|---|
| Optical Design | Apochromatic Doublet Refractor |
| Aperture | 51 mm / 2" |
| Focal Length | 250 mm |
| Focal Ratio | f/4.9 |
| Focuser | Dual-Speed Rack-and-Pinion |
| Weight | 5.25 lb / 2.38 kg |
| Optical Tube Assembly | |
| Optical Design | Apochromatic Doublet Refractor |
| Aperture | 51 mm / 2" |
| Focal Length | 250 mm |
| Focal Ratio | f/4.9 |
| Focuser | Dual-Speed Rack-and-Pinion |
| Diagonal | No |
| Finderscope | No |
| Mounting | Vixen Style |
| Optical Tube Dimensions | 13.6" / 346 mm |
| Mount | |
| Payload Capacity | No |
| Altitude Adjustment | No |
| Latitude Adjustment | No |
| Counterweight | No |
| General | |
| Weight | 5.25 lb / 2.38 kg |
| Packaging Info | |
| Package Weight | 8.935 lb |
| Box Dimensions (LxWxH) | 16.6 x 10.7 x 9.5" |
William Optics Cat 51 WIFD f/4.9 Apochromatic Telescope with ZWO AM5N Mount Kit
- Product Code: WILRC51RDI5K
From the high-end Petzval lens on the optical tube assembly to the precise strain-wave gearing of the mount, the William Optics Cat 51 WIFD f/4.9 Apochromatic Telescope with ZWO AM5N Mount Kit from B&H will help you capture brilliant images of the night sky. The telescope features an innovative center-of-tube focus mechanism and creates an image circle large enough for full-frame camera sensors, while the sturdy, compact mount effortlessly moves the scope to track your subject throughout the exposure. This kit includes the OTA and the mount; you'll only need to supply a tripod.
William Optics Cat 51 WIFD 51mm f/4.9 Apochromatic Refractor Telescope (OTA Only)
Designed for stargazing and astrophotography, the Cat 51 WIFD 51mm f/4.9 Apochromatic Refractor Telescope from William Optics uses an unorthodox design for supporting heavy cameras and delivers a wide field, a fast focal ratio, and a Petzval lens for beautiful images. The WIFD (William Optic Internal Focus Design) places the 10:1 rack-and-pinion focuser in the center of the optical tube, eliminating the tilt and vignetting that can occur from heavy cameras on traditional rear-mounted focusers. A four-element Petzval-style lens yields a sharp image with no need for a flattener and the dust cover has a built-in Bahtinov mask for tack-sharp star images. This optical tube assembly requires a mount and a tripod for use.
Optical Tube Assembly
- Fast f/4.9 focal ratio and 250mm focal length for wide field of view and fast exposure times
- Apochromatic Petzval-style four-element lens produces rich views with minimal chromatic aberration
- Sharp image with no need for a separate field flattener
- Supports 48mm image circle for full-frame, APS-C, and micro four thirds cameras
- Dust cover with integrated Bahtinov mask allows for fine focusing on stars
- Built-in tilt adapter
- Camera angle rotation device
- M54 female thread for cameras, accessories, or eyepiece diagonals
Focuser
- William Optics Internal Focus Design places focuser in center of OTA to balance the weight of imaging systems
- Precise internal sliding of fixed optics prevents image shift, ensuring stable and clear observations
- 10:1 coarse and fine focus rack-and-pinion design
- Compatible with ZWO EAF automatic focuser
- 0-23mm focus travel, ruler to 30mm
Dial-style thermometer for gauging temperature effect on optical tube
Use and Handling
- Anodized aluminum optical tube
- Sturdy mounting ring and handle assembly with 210mm Vixen-style dovetail
- Additional dovetail with thumbscrews on handle for guidescope or other accessory
ZWO AM5N Harmonic Equatorial GoTo Mount
Designed with a strain wave gear reducer and synchronous belt for precise control, the ZWO AM5N Harmonic Equatorial GoTo Mount offers alt-az operation for observation and go-to equatorial tracking for astrophotography via a smartphone app or an ergonomic hand controller. The mount weighs just 12.1 pounds but can support payloads up to 33 pounds on its own or 44 pounds with a user-supplied counterweight and shaft. A brake system ensures the mount won't topple in the event of a power failure. The mount runs on a user-supplied 12V, 5A power supply and is compatible with ASCOM and ZWO's ASIAIR platforms.
Low Weight, High Payload
- Weighs 12.1 lb
- Supports 33 lb without counterweight
- Payload increases to 44 lb with optional 11 lb counterweight
- 3/8"-16 tripod mount
Strain-Wave Gear for Precision Control
- Strain-wave gearing system comes with very low ±10" periodic errors, smooth gearing, and high torque
- Reduction ratio is 300:1
- Each mount is tested and shipped with a periodic error curve report
Dual AZ/EQ Modes
- Capable of both equatorial and alt-azimuth modes
- Suitable for both visual and imaging
- Elevation angle of 0-90°
- Can be used anywhere from the equator to the polar regions
Mode Indication
- Red light is displayed for equatorial mount mode
- Green light is displayed for alt-azimuth mode
- If the mount has no synchronization, the indicator light flashes alternately red and green, and the corresponding color indicator light will be displayed according to the mode after synchronization
Joystick Handset or App Control
- Control via the included hand controller or from your phone or tablet using the AM5 app
- App offers an onscreen joystick combined with convenient tools including Best Objects of the Evening, a built-in star map with real-time display and GOTO functions
- There is no need to connect to a computer—the mount and hand controller connect via Wi-Fi
- The mount is compatible with ASCOM, INDI, ASIAIR, and other platforms
Power-Off Braking
- In the event of power failure, brakes are instantly applied to prevent the telescope and equipment from falling and resulting in damage or injury
Ports for Cable Management
- 12 VDC input and USB-C ports on saddle reduce cable tangling
- 12 VDC output supplied from the main body power socket, this outlet can share power with devices such as ASIAIR
- The mount is powered by a user-provided 12V, 5A power supply
Key Features
- 250mm Focal Length, f/4.9 Focal Ratio
- Center-Balanced Internal Focus Design
- For Full-Frame, APS-C, Micro 4/3 Cameras
- Strain-Wave Motorized Mount
- Control by App or Hand Unit
- EQ & Alt-Az Modes
- Precise 300:1 Reduction Ratio
- Supports 33 lb Without Counterweight
- Bahtinov Cap
- M48 Cap
- Mounting Ring with Handle
- Dual Mounting Plate
- Mounting Ring Handle Bar
- Allen Key Set
- Soft Carry Case
- Limited 2-Year Manufacturer Warranty
| Key Specs | |
|---|---|
| Optical Design | Apochromatic Doublet Refractor |
| Aperture | 51 mm / 2" |
| Focal Length | 250 mm |
| Focal Ratio | f/4.9 |
| Focuser | Dual-Speed Rack-and-Pinion |
| Weight | 5.25 lb / 2.38 kg |
| Optical Tube Assembly | |
| Optical Design | Apochromatic Doublet Refractor |
| Aperture | 51 mm / 2" |
| Focal Length | 250 mm |
| Focal Ratio | f/4.9 |
| Focuser | Dual-Speed Rack-and-Pinion |
| Diagonal | No |
| Finderscope | No |
| Mounting | Vixen Style |
| Optical Tube Dimensions | 13.6" / 346 mm |
| Mount | |
| Payload Capacity | No |
| Altitude Adjustment | No |
| Latitude Adjustment | No |
| Counterweight | No |
| General | |
| Weight | 5.25 lb / 2.38 kg |
| Packaging Info | |
| Package Weight | 8.935 lb |
| Box Dimensions (LxWxH) | 16.6 x 10.7 x 9.5" |
- Brand: William Optics
- Product Code: WILRC51RDI5K
- Availability: In Stock
$1,999.00
Tags:William OpticsCat 51 WIFDf/4.9 APORefractor TelescopeZWO AM5N MountAstrophotographyStar GazingAstronomy KitHigh-End TelescopeNight Sky Viewing
