William Optics RedCat 61 WIFD f/4.9 Petzval Refractor Telescope - Red

William Optics RedCat 61 Overview

Introducing the latest member of the RedCat family: the William Optics RedCat 61. Featuring the patented new William Optics Internal Focus Design (WIFD) and an image circle of 46mm, this RedCat 61 is an extremely robust wide field imaging telescope capable of producing fantastic images.

William Optics RedCat 61 WIFD Review

Agena Astro Affiliate and well-known astrophotographer AstroBackyard wrote a detailed review on their website as well as created this review video of the William Optics RedCat 61 WIFD:

Upgraded William Optics Internal Focus Design (WIFD)

If you had to pick one flaw about the existing RedCat 51 and RedCat 71 — which there aren't many — it would be that the helical style focuser means that third party accessories must be used to adapt an autofocuser. The RedCat 61 corrects that and then some. Featuring the all-new, William Optics Internal Focus Design (WIFD), the RedCat 61 is now compatible with autofocuser options like the ZWO EAF right out of the box.

Experienced imagers know that sensor tilt can be a major pain to correct. Sensor tilt is when the focuser drawtube sags under the weight of the camera and accessories, which then throws part of the sensor out of focus, resulting in elongated stars on one part of your image. With the new WIFD in the RedCat 61, the focuser drawtube now housed inside the telescope itself, which virtually eliminates sensor tilt and vignetting in your images. It can carry heavy image trains with a camera, filter wheel, off axis guider, and more with ease, and features both M54 and M48 threads for attaching accessories. All of this can be easily rotated with the built in 360-degree rotator on the back.

Please note: The focuser travel does not extend over the full range of the markings shown on the telescope tube. This is normal in all WO WIFD/Pleiades telescopes and not a defect in your particular unit.

Premium FPL-53 Optics & Petzval Design

Like its cousins, the RedCat 61 also features premium FPL-53 glass, which is among the best available glass for refractor telescopes today. This high-quality glass ensures excellent image quality and a large 46mm image circle. The Petzval optical design features a built-in flattener so you're ready to image right away without buying an extra field flattener. The Petzval design also means you don't need to worry about dreaded back focus. Simply reach focus with your camera, and you can be reassured that you're getting the flattest field possible. This also leaves an extra few millimeters for additional accessories.

RedCat 61 Focal Length, Aperture, and Weight

The RedCat 61 focal length is 300mm, which sits right between the RedCat 51's 250mm and the RedCat 71's 350mm. Its aperture is a relatively fast f/4.9, which is identical to the other RedCat telescopes. Despite having a new focuser design that adds weight, the RedCat 61 still weighs a mere 7.5 lbs (3.4 kg) with everything attached (tube rings, dovetail, and CAT saddle). That means you can take it anywhere, and even use it on today's popular star tracker mounts. William Optics also offers a 1.25" 90-degree diagonal (sold separately) so you can now use this scope with eyepieces for visual use too.

Designed for Wide Field Astrophotography

The RedCat 61's focal length of 300mm is ideal for wide field astrophotography of large nebulae, galaxies, and the Milky Way. The shorter focal length also makes it very forgiving for beginners because it doesn't require as precise of tracking with a mount. 

RedCat 61 Included Accessories

Included with the RedCat 61 are tube rings, a longer CAT series handlebar and Vixen saddle for attaching a guide scope or other accessories, a dew shield cover with patented built in Bahtinov Mask, and a longer dovetail bar for easier balancing. All of this fits into a quality soft shell case that can fit in many luggage bags for easy travel.

RedCat 61 Sample Image

Sample image of the Propeller Nebula taken with the William Optics RedCat 61 telescope by AstroBackyard / Trevor Jones

RedCat 61 Specifications

• Lens Type: 4-Element Petzval Design
• Focal Length: 300mm
• Diameter: 61mm
• Aperture: f/4.9
• Image circle: 46mm
• Focuser: WIFD R&P Focuser, Compatible with ZWO EAF
• Focus Travel: 0 - 42mm (Ruler to0-50mm)
• Adapter Included: Tilt Adjuster, M60 to M54 Rotator, M54 to M48 Adapter
• Optional Flattener: No Flattener required
• Camera Format: Full Frame, APS-C, M4/3
• T-Mounts Supported: Canon EF / RF, Nikon F/ Z,  Sony E, Pentax K, Micro Four Thirds (M4/3), FUJI X
• Tube Length: 365mm
• OTA Weight: 5.43lbs / 2.47 kg
• Total Weight: 7.47lbs / 3.39 kg (OTA with ring, dovetail and saddle)
• Soft Carrying Case External Dimensions: 44x23x24.5 (cm)