Tele Vue Adpater to Use Dioptrx Astigmatism Correcting Lenses with all Type 6 Nagler Eyepieces

2010-07-25T21:00:00

At 2.25 diopters, my astigmatism becomes bothersome in any exit pupil over 2 mm. Since I observe with f/5 scopes, this means my enjoyment of the 11 and 13 mm type 6 Naglers is compromised. This adapter provides a flange which accepts both the dioptrx astigmatism corrector and the standard 2" rubber eyeguard found on many TeleVue eyepieces. The flange lies flush, or slightly below the eye lens, so there is no loss of eye relief when in use. Using the dioptrx with its eyeguard folded down, I can rest my brow on the eyeguard and easily take in the entire field--in fact, relative to the eye lens, my eye is in the same position it would be without the dioptrx. Granted, the eye is quite a bit closer to the dioptrx itself than to the eye lens, but not uncomfortably so. Now, in viewing a rich open cluster, astigmatism correction is really vital, but in certain situations, this correction is less important than transmission--as when viewing faint galaxies. So you may want to remove the dioptrx from time to time. Moreover, some observers do not like the standard hard eyeguard that comes with the type 6 Naglers. A nice feature of this adapter is that it allows you to use the 2" eyeguard found on most 2" TV eyepieces. In use with the type 6, this provides superior light baffling. The eye relief is just sufficient that one can rest one's eye brow on the edge of the eyeguard and take in the full field, with the eye fully shielded from ambient light. Overall, this is a well-engineered adapter that works great, with or without the dioptrx.

GEORGE G.