Televue Nagler 82-deg FOV Eyepiece - 31mm

CA$855.00
Model # EN5-31.0
Focal Length (mm) 31
Barrel Size (in.) 2"
Apparent Field of View (deg.) 82
Eye Relief (mm) 19
Weight (lb / oz) 2.20 / 35.2
Field Stop (mm) 42

With the 31mm, the unique 6-element design using four exotic glasses, maintains the contrast advancement of the Type 4s while achieving a true field area 82% larger than the 22mm Type 4! Owners of fast Dobsonian/Newtonians can enjoy a larger true field, free of secondary shadowing, than ever before. For example, a 12.5", f/4.5 scope with a Paracorr will deliver a 1.5 degree field (3 Moon diameters), at 53x with a 6mm exit pupil. Use our eyepiece calculator to figure out what the 31mm will deliver on your scope.

Why Are There 3 Types of Naglers?

To achieve the full magnification range over 82° apparent field of view requires two types: Nagler Type-5 with focal lengths of 3116mm and Nagler Type-6 with focal lengths of 13119753.52.5mm.

The Type-5 permits the largest true field possible (31mm has 42mm field stop).

Type-6 models have shorter focal lengths, are parfocal, with similiar size and weight, and all with a comfortable 12mm eye relief.

The Type-4 models feature about 18mm of eye relief and with the "instajust" eyeguard are best for eyeglass wearers or Dioptrx users in their 221712mm focal length range.

EN5-31.0