With the 31mm, Tele Vue's 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.
| 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 |