Celestron Omni 1.25" Plöss Eyepiece - 6 mm Focal Length, 50° Field of View

Celestron Omni Series 1.25" - 6 mm

Many low-priced beginner´s telescopes are delivered with cheap eyepieces which are sufficient for a first glance through the telescope, but soon want you to have something better - small field of view or an uncomfortable short eye relief spoil the observations. Simple eyepiece designs according to Kellner, Ramsden or Huygens (marked K, SR or H) are not up to date anymore - despite they are advertised as "high performance eyepieces".

With the Omni eyepieces, Celestron offers an economically priced alternative. They are Plössl eyepieces with a symmetrical four-element design. Blackened lens edges prevent from internal reflections and increase the contrast, the multi-coating on each element allows for maximum contrast and light transmission. Additionally, every cell is anodized twice for preventing reflexions - oher manufacturers will supply reflecting surfaces instead.

The 6 mm Plössl is a powerful planetary eyepiece and thus a typical eyepiece for observing planets or close double stars. Using a Barlow lens makes sense only with telescopes of short focal length and large aperture, otherways the maximum useable magnification (double the aperture in mm) might be exceeded.

But this eyepiece with only 5 mm eye relief is not suitable for spectacle wearers. Observers which are only far or near sighted can use the eyepiece without eyeglasses; if the eyglasses correct more defects of vision, like astigmatism, an eyepiece of longer focal length, combined with a suitable Barlow lens, or a more expensive eyepiece design with more eye relief might be more sensible.