TeleVue 55mm Plössl Eyepiece

If you have a 2" focuser on your f/8 and longer focal ratio telescope, here's a 2" eyepiece that will give you the widest possible field of view - even wider than a 31mm Nagler, but at less than 40% the cost. (The 31mm Nagler is designed to give maximum brightness and field of view on a fast focal ratio Dobsonian, not a long focal ratio refractor, Schmidt-Cassegrain, or Maksutov-Cassegrain, as is the 55mm Plössl.) This is a good low power/wide field eyepiece that provides the widest field and largest exit pupil possible with an f/10 Schmidt-Cassegrain for true rich field observing. It's ideal for capturing many of the more compact open clusters such as the Pleiades, viewing emission and reflection nebulas in their entirety, scanning large and faint nebula remnants such as the Veil, etc. You can use the calculator below to see how wide a field it will give you with your particular focal length scope. It has a rubber grip ring for comfortable use in cold weather. It provides an immense and wasteful 12.2mm exit pupil with an f/4.5 Dobsonian reflector. As the only observers whose eyes can dilate to this size are probably owls, this eyepiece would not be a sensible choice for fast focal ratio reflectors. It is better suited to the longer focal ratios of refractors, Schmidt-Cassegrains, and Maksutov-Cassegrains than it is to reflectors with focal ratios shorter than f/8. If you have a long focal ratio 2" focuser scope, however, this is a terrific way to get the most out of it. The eye relief is long enough to allow eyeglass wearers to see all of the field with their glasses on, yet it's not so long that those who don't wear glasses will find observing uncomfortable. The eyepiece is provided with a unique adjustable height eyeguard adapter that aids in properly positioning your eye in the exit pupil. This minimizes "pupil shadowing" and reduces stray light to maximize contrast. The soft rubber eyecup can be used fully extended or rolled back, whichever is more comfortable. You can also selectively extend one side of the eyecup to shield your eye from external light (such as a neighbor's porch light). Tech Details: Barrel Size 2" Eye Relief 20mm Field of view 50 Focal Length 55mm Number of optical elements 4 Weight 21 oz Warranty 5 years