The Most Common Types of Telescope Eyepieces

The enormity of the Universe offers plenty of opportunities for observation. Before, space observation was only reserved for high-powered instruments located in enormous observatories. Now, an array of telescopes on the market has made it possible for enthusiasts to watch and record celestial objects from the comfort of their own homes. In fact, Redskins 101 reports that the global astronomical telescope market is expected to reach $428.8 million in 2028, with an annual growth rate of 8.4%.

Telescopes rely on advanced optical principles to do the job through gigantic lenses and sturdy support systems. Budding astronomers can consider starting with small refracting telescopes offered at reasonable prices. These are usually packaged with a metal tripod, a basic mount, and a finder. To double their magnification, eyepieces can be upgraded along with the lenses. In this article, we will discuss four of the most common telescope eyepieces you can find on the market today.

1. The Plössl eyepiece

Plössls comprise four glass elements arranged as two back-to-back achromatic doublets. They have a wide field of view ranging between 50° and 56°, which is perfect for planetary and deep-sky viewing. With the adequate field of view it provides, a Plössl eyepiece is often bundled with new telescopes or at least is provided at a reasonable cost. Meade’s Super Plossl is one classic design introduced in the 1990s. It innovates from the traditional Plossl design by adding a fifth glass element on top of the two pairs while keeping the symmetrical design. Although a couple of eyepieces are available in the market today, Plössls continue to hit the right spot between high-quality optics and price.

2. The Radian eyepiece

The Radian eyepiece offers a field of view similar to the Plössls, but it provides huge eye relief with focal lengths down to 3mm. With its short focal length oculars and its lightweight design, its selling point is the convenience it gives its users. For eye-glass-wearing enthusiasts, the Radian can allow for longer observation times without too much eye strain, all while obtaining the same depth and detail as other eyepieces. Its design suits medium and higher magnifications, with six to seven lens elements and very short focal lengths in its internal mechanism. This proprietary design offered by the Radian is one of the newer ones in the market.

3. The Nagler eyepiece

Designed in 1970 by Al Nagler, the Nagler eyepiece initiated the revolution toward ultra-wide field eyepieces. Its most notable attribute is its vast field of view, going the extra mile with an ultra-wide 82° field. This makes it possible to observe the fantastic vistas of starfields and nebulae. The Tele Vue Nagler type is one of the best-selling telescope eyepieces on Adorama, coming with blackened lens edges, anti-reflection threads, and rubber eye guards. It is also designed with seven elements using different exotic materials and coating processes. With focal lengths that come in 13mm, 9mm, and 7mm, the Nagler eyepiece provides the perfect medium to high power for home astronomers who want to upgrade their equipment.

4. The Orthoscopic eyepiece

An Orthoscopic eyepiece is made with a four-element optical system that effectively keeps down the amount of light refraction while providing some eye relief. Astronomy enthusiasts often use this eyepiece to observe the Moon and the planets, with its 40° to 45° field of view. Although the three previously mentioned eyepieces have primarily captured the market for eyepieces, the Orthoscopic eyepiece still finds great application for amateur skygazers who want to explore astronomical observation as a new hobby.

Telescopes remain the popular choice in the field of astronomy, as we previously discussed in our post on ‘Binocular vs. Telescope: What’s Best for Astronomy?’ Having the proper equipment to provide you with our desired field of view and eye comfort will make stargazing, moon-watching, and planetary observation much more enjoyable.