Celestron Ultima Duo 21mm eyepiece Telescope 2 cm Black

Get a new perspective on the Universe with Ultima Duo, Celestron's versatile new eyepieces that combine excellent optics with a built-in T-adapter for astroimaging.

Enjoy impressive views with a wide 68-degree apparent field of view. Celestron’s fully multi-coated optics increase light transmission and contrast, while blackened lens edges prevent internal reflections. The result is bright, pinpoint stars on a black field. A generous 20mm of eye relief and fold-down rubber eyeguard make Ultima Duo comfortable to use without removing eyeglasses.

Perfect for Imaging
If you’re interested in imaging through the eyepiece, Ultima Duo makes the process quick and easy. Unlike competitors’ eyepieces, you won’t need to spend money on expensive adapters for your camera. The industry-standard 42 mm T-threads are integrated for a direct, secure connection to your DSLR or astronomical CCD camera. Just remove the rubber eyeguard to expose Ultima Duo’s integral T-threads. Then attach your DSLR camera (with compatible T-ring) and you’re ready to capture crystal clear images! Ultima Duo is ideal for imaging bright solar system objects like the rings of Saturn, craters on the Moon, and Jupiter’s Great Red Spot.

Imaging the Moon and planets is even easier with our Smartphone Adapter for Ultima Duo. Unlike “universal” adapters, the Celestron Smartphone Adapter is custom-fit for the Ultima Duo eyepiece line. With this sturdy connection, your smartphone can capture crisp, sharp images of your favorite solar system objects.

Advanced planetary imagers can attach Celestron’s T-to-C Adapter and add a number of high-end imagers to Ultima Duo, including our Skyris and NexImage Burst cameras.

Smart Design for Use in the Field
Ultima Duo’s anodized aluminum body allows it to fit both 1.25” and 2” focusers, so you can use it with almost any telescope with no extra adapters required. A compact body style makes Ultima Duo an excellent choice for use with binoviewers.

The rubber grip rings provide good ergonomics so you can hold onto your eyepiece, even while wearing gloves. The aluminum barrel is threaded to accept 1.25” eyepiece filters and has a safety recess to prevent it from slipping out of the focuser. Each Ultima Duo eyepiece includes cover caps and a protective carry pouch.