William Optics Cat 61 WIFD

The William Optics Cat 61 WIFD is a compact 61mm f/4.9 Petzval astrograph designed for wide-field deep-sky astrophotography, portable imaging, and full-frame camera support. With a 300mm focal length, 46mm image circle, and William Optics Internal Focuser Design, it gives astrophotographers a small but capable imaging telescope with a flat field and stable focusing.

Who Is This Product Best For?

The Cat 61 WIFD is best for beginner to intermediate astrophotographers who want more aperture and reach than a 51mm astrograph while still keeping the system compact and travel-friendly. It is also useful for advanced imagers building a lightweight secondary wide-field rig.

Why Choose This Product?

• 61mm aperture: More light gathering than smaller travel astrographs.
• 300mm focal length: Ideal for wide nebulae, star fields, and larger deep-sky targets.
• 4-element Petzval design: Flat-field imaging without a separate field flattener.
• 46mm image circle: Supports full-frame, APS-C, and Micro Four Thirds cameras.
• WIFD focuser: Helps maintain focus stability with camera accessories.

Recommended Uses

• Wide-field deep-sky astrophotography
• Nebula and star-field imaging
• Portable astrophotography setups
• Full-frame, APS-C, and Micro Four Thirds imaging
• Lightweight equatorial mount systems

Compatibility and Accessory Notes

The Cat 61 WIFD includes a tilt adjuster, M60 to M54 rotator, and M54 to M48 adapter. It supports common camera mount ecosystems including Canon EF, Canon RF, Nikon F, Nikon Z, Sony E, Pentax K, Micro Four Thirds, and Fuji X. Customers should confirm camera adapter, focuser, guide scope, and mount capacity needs before purchase.

Important Limitations

The Cat 61 WIFD is primarily an astrophotography telescope. It is best recommended for customers building an imaging system rather than customers looking for a simple visual observing telescope.

Frequently Asked Questions

Is the Cat 61 WIFD good for beginners?

Yes, it can be a strong beginner astrophotography telescope when paired with a suitable tracking mount and camera.

What type of astrophotography is it best for?

It is best for wide-field deep-sky imaging, including nebulae, star fields, large galaxies, and travel imaging setups.

Does it need a field flattener?

No. Its 4-element Petzval design provides a flat imaging field without a separate flattener.

What camera formats work with it?

It supports full-frame, APS-C, and Micro Four Thirds cameras.

Our Recommendation

The William Optics Cat 61 WIFD is a strong choice for astrophotographers who want a compact, full-frame-capable Petzval astrograph with more reach than a 51mm model. Choose it for portable deep-sky imaging, large nebulae, and simple flat-field camera setups.

Optical Diagram Reports

The following optical report graphics are included for customers who want to review optical performance.