William Optics Redcat 51 WIFD F/4.9 Petzval Refractor

As seen on the RedCat 61 series, the patented William Optics Internal Focus Design (WIFD) makes its debut on the RedCat 51 series! The addition of the WIFD system brings something that RedCat 51 fans have all been waiting for: out-of-the box electronic focuser compatibility. No more 3rd party belt systems are needed, and easy to follow instructions are provided on exactly how to attach the popular ZWO EAF within the manual. This innovation from William Optics provides the ultimate Apochromatic refractor for astrophotography!

This internal focusing design does not shift the length of the OTA in any way, as the optics themselves move within the telescope as opposed to the camera moving. This prevents vignetting seen with traditional rear mounted focusers, and allows for a better redistribution of weight for improved balance of your optical assembly during your night of imaging. This WIFD apparatus offers the ability to automate your astrophotography set up with an electronic automatic focuser as well! When pairing this innovative technology with the high quality Petzval design of the RedCat series, William Optics delivers a telescope with outstanding astrophotography performance.

Integrated Tilt Adapter

Maximizing your image quality is the easy to use tilt adapter. If needed, this tilt adapter adjusts the angle your camera sits at for a sharp focus all the way across your frame. Simply remove the back cover of the telescope and adjust the screws on this adapter in a push or pull manner for trouble-free alignment.

Included 2" Filter Holder

This WIFD RedCat 51 has a built-in M48 filter holder, allowing great versatility in your set up! Easily swap out your favorite filters for different types of imaging. To insert a filter, remove the camera adapter and screw in your 2" filter, then simply reattach the adapter and you're all set!

Unparalleled Performance with Endless Accessories!

This featured packed WIFD RedCat 51 telescope is sure to take your astrophotography to the next level. Whether through the high quality optics, the robust internal focuser, or the endless included accessories, see why this apochromatic refractor is a must have for any astrophotographer!

Pristine Optics

Adopting a Petzval design, this WIFD RedCat 51 provides a flat imaging field right out of the box! A 45mm imaging circle allows for sharp stars all the way to the corners, even with a full frame camera. There is also no need to worry about finding the perfect backfocus for your sensor with this Petzval telescope style. As long as you reach focus, your camera will be at the correct spacing needed. The quadruplet design and FLP-53 glass offers four correcting lens elements which results in virtually zero chromatic aberration for superior optical performance. The 51mm aperture offers incredible light gathering abilities over a wide field of view with 250mm in focal length. With its fast f/4.9 focal ratio, produce beautiful images with less integration time.

A Rock-Steady Focuser Design with EAF Compatibility
Typical focusers work by moving your imaging or visual equipment forwards and backwards until it is at the focal plane formed by the optics. This works well, however does come with some drawbacks - mainly the possibility for sag in the drawtube with heavier payloads and further extension, and vignette of the maximum possible image circle. William Optics’ WIFD system eliminates these concerns by moving the optics inside the telescope, which means a solid, static, mount for your equipment and a large path for the stellar optics in the WIFD RedCat 51! All of this is supported by a solid Rack & Pinion mechanism, which you can adjust with the 10:1 dual speed knobs. For those seeking motorized focusing however this new system also brings with it the long awaited ZWO EAF compatibility feature! The WIFD RedCat 51’s focuser has dedicated mounting points for the EAF and similar style electronic focusers, which makes motorizing your scope a breeze. Other small improvements from the switch to this focuser design include a more standard focuser tension/ lock adjustment, and tidier cable management (a stationary back means no more leaving slack!).

The Complete Package
William Optics has included a plethora of accessories to complete this WIFD RedCat 51 III package. In addition to your telescope, you will find a dust cover with the innovative William Optics Bahtinov mask, a dew shield, a saddle handlebar, a camera angle rotator, a 210mm Vixen-style dovetail plate, and a soft carry case. Each of these accessories is designed to aesthetically match your refractor OTA, as well as enhance portability, function, and attachment capabilities. For example, the included handlebar pulls double duty by allowing an easy way to carry your OTA from one place to another, as well as providing an opportunity to mount compatible accessories, such as a user-supplied William Optics Uniguide or the Apertura 32mm guide scope. Worried about traveling to a star party and keeping your optics safe? William Optics has you covered with the soft carry case. The dust cover and dew shield also offer protection for your optics during times of storage or when in use.

Powerful and Portable
The William Optics RedCat 51 WIFD refractor is a testament to how a high performance does not always equal large, bulky equipment. This APO refractor OTA weighs only 3.0 lbs (1.77kg). When the included rings, dovetail, and saddle are added, this increases to only 5.25 lbs. (2.38kg). Additionally, as mentioned above, William Optics have included accessories that only increase the portability of this RedCat 51 scope: the soft carry case and saddle handlebar. Portability and traveling can be incredibly important when it comes to imaging your desired celestial objects. This WYO refractor pairs nicely with portable mounts like the Sky-Watcher GTi mount or a full GoTo mount like the ZWO AM3 or AM5. With the light-weight design and a tube length of 11.7” (298mm), you should have no problem taking this small, but mighty refractor with you on any of your astroimaging adventures.

Technical Specifications 

In the Box

• William Optics 51mm Gen 3 RedCat

• Dust Cover with Bahtinov Mask

• 210 mm Vixen Dovetail

• Mounting Ring

• Soft Carrying Case

• Dew Shield

• Tilt Adjuster

• Camera Angle Rotation Device

• Saddle Handle Bar

Warranty & Manuals

William Optics 2-Year Warranty