Orion 10mm, 17mm & 25mm Sirius, 1.25" Plossl Starter Eyepiece Set with 52 Degree Angle of View

The Orion Sirius Plossl Eyepieces offers a wide 52° apparent field of view providing extremely sharp images of impressively high contrast. They're ideal for all types of telescopes: reflector, refractor and catadioptric. The Plossl 4-element design is renowned for its outstanding performance and has become the standard by which all other eyepieces are judged.

The Sirius Plossl optical system is fully coated with magnesium fluoride on every air-to-glass surface. Lens edges are blackened to reduce scattering of stray light and maximize contrast. The lenses are mounted in black-anodized aluminum housings with 1.25"-diameter chrome-plated brass barrels for durability and precision fit. Each barrel is internally threaded to accept standard filters. The built-in rubber eyeguards enhance viewing by helping to block out ambient light and position the eye.

The 10mm is a great, moderately high power ocular for observing small planetary nebulas and globular star clusters, as well as for planetary probing when seeing conditions don't permit higher magnifications. A medium-power eyepiece, the 17mm is perfect for broad-field lunar observations, medium-sized star clusters and a wide range of nebular objects. For moderately low power scanning of open star clusters and viewing of extended nebulas and larger galaxies, the 25mm model excels.