William Optics WIFD Ultra-Cat 76 APO Refractor
Introducing the Ultra-Cat 76 WIFD APO Refractor!
If you’re in search of top-tier imaging performance, this William Optics Ultra-Cat 76 is the telescope for you. With 5 internal lens elements composed of high quality glass, you can expect stunningly sharp, well-corrected astrophotos! As a Petzval refractor, there is no need for an additional field flattener nor backspace calculation, making camera attachment a breeze. Stars will be sharp across the entire field of view, even for medium-format and full frame cameras! Thanks to the innovation from William Optics, this Ultra-Cat 76 APO Refractor is sure to take your astrophotography to the next level.
The 76 mm aperture paired with the 365 mm focal length results in a focal ratio of f/4.8, making this a speedy system for deep space imaging. Featuring an incredibly large image circle of 50 mm, the William Optics Ultra-Cat 76 supports medium-format and full frame cameras for stunning wide field images. In addition to these superior optics, this APO telescope comes furnished with the William Optics Internal Focus Design (WIFD) for smooth, stable focusing. You even have the ability to attach an electronic autofocuser (not included) to this telescope for automatic, hands-free focusing. With features like these, the William Optics Ultra-Cat 76 is the ultimate tool for astrophotographers eager to capture breathtaking images of our universe.
Powered By Five Internal Lenses
Unlocking a world of imaging possibilities, this William Optics Ultra-Cat 76 is a must have for those looking to capture outstanding astroimages. The William Optics Ultra-Cat 76 is built with quality in mind, housing a total of five lenses with one X-element, one Lanthanum, one ED, and two Super ED glass elements These lenses work together to eradicate coma, field curvature, and any other aberrations, resulting in unparalleled color correction and clarity. One key benefit from this quintuplet design is an inherent flat field, meaning you can expect pinpoint stars from edge to edge across the massive 50 mm image circle. Additionally, there’s no need to calculate backfocus! As long as you can reach focus, the entire frame will be in focus as well. Finely engineered, the anti-shrink lens cell technology reduces the thermal expansion effects in any climate, ensuring perfect optical alignment night after night. With these outstanding optics, easily resolve stunning structure within galaxies, beautiful detail within nebulae, and stark definition of star clusters!
Engineered for Excellence
This William Optics Ultra-Cat Refractor delivers superb images with its sophisticated 5-lens optical design, making it a premier instrument for astrophotography. Its innovative focuser provides a steady, solid mount for your imaging train, ensuring maximum image quality. Read more below as we highlight these impressive astrophotography capabilities and the William Optics Internal Focus Design (WIFD) included within this Ultra-Cat 76!
An Astrophotography Powerhouse
Powered with impressive specs, the William Optics Ultra-Cat 76 offers an extensive range of targets for capture! The large 76 mm (3”) aperture soaks in the light for beautiful detail within your frames. At a 365 mm focal length, popular nebulae like the Orion Nebula, the Lagoon Nebula, and the North American Nebula are wonderful choices. In addition to nebulae, take a deeper look into space past our own Milky Way to resolve stunning detail on large galaxies like the Andromeda Galaxy and the Triangulum Galaxy. This medium-format powerhouse is built with a considerable 50 mm image circle, enabling compatibility with most of today’s largest sensors! Rapid light collection is another key benefit of this William Optics Ultra-Cat 76 thanks to its rated f/4.8 focal ratio. Included within this package are two adapters: an M54 and an M48. These additions help you seamlessly join your imaging train to your refractor, allowing you to get out and under the stars in no time!
WIFD Focuser Design with EAF Compatibility
Instead of moving your imaging train forwards and backwards to find focus, this William Optics Ultra-Cat 76 APO refractor houses an internal focuser, moving the optics internally to find focus instead. By holding your imaging train steady, the possibility of drawtube sag is greatly diminished, especially for heavier imaging equipment. This also reduces the chance of any vignetting due to drawtube instability, resulting in higher image quality. If you’d like to automate your focusing routine, this focuser is also EAF ready!
Included Sensor Tilt Xterminator
Helping you eradicate tilt, William Optics has added their innovative Sensor Tilt Xterminator with thisUltra-Cat 76! This new and improved tilt adjuster refines the original 4 pull-in and 8 push-out screw configuration, introducing a new, more efficient 4 push-out and 4 locked screw system. This “seesaw-style” adjustment mechanism allows you to make quick adjustments without having to remove your camera. Just loosen one screw and tighten the opposing diagonal screw until you’ve found proper alignment!
Jumpstart Your Imaging Sessions with these Added Extras!
In addition to the Sensor Tilt Xterminator, William Optics includes a plethora of additional accessories out of the box! As a William Optics signature feature, the objective cap doubles as a handy Bahtinov mask. For dew prevention and stray light control, the dew shield of this telescope is retractable. Simply extend this dew shield during imaging, and lock it in place with the locking screw to ensure a stable position all night long. A convenient focus ruler is built into the body of this refractor, enabling a quick return to previous focusing positions. On the coarse focusing knob, you’ll find a temperature gauge. This thoughtful feature enables precise monitoring of nighttime temperature shifts for systematic telescope refocusing. For addition of a user-supplied finder base, M4 screw holes can be found on the side of this telescope. The dual-use handle bar enables attachment of extra accessories as well! Also included are mounting rings to keep your refractor secure, and a 210 mm dual-sided (Vixen-style & Arca Swiss Type) dovetail plate.
Astronomy Hub: Your one-stop-shop for Astrophotography Knowledge!
Our Gear Experts have compiled a wealth of information to help expand your astrophotography knowledge! Below you’ll find links to articles, videos and "how-to" guides. Just one more reason that our Astronomy Hub is a one-stop-shop for all your astronomy and astrophotography needs!
| Achieving Perfect Focus with a Bahtinov Mask |
| Autoguiding |
| Telescope Mount Buying Guide |
| ZWO ASIAir Ultimate Guide |