About the TeleVue 17mm Nagler Type 4 Eyepiece - 2"...
Applying the experience of the TeleVue Telescope Eyepiece Radian development to the 82 degree Nagler series, yielded more contrast, reduced pincushion, more true field, and longer eye-relief. With added eye-relief, the click-stop Instadjust eyeguard incorporated into the TeleVue 17mm Nagler Type 4 Eyepiece helps maintain proper eye distance and centration.
Compare a penny to a half dollar to see the relative size between a 50 degree and 82 degree apparent field - almost 3 times the area difference! And while other telescope eyepieces boast of impressive apparent field sizes, Tele Vue''s philosophy of "showing no field unless it''s fine" stresses full field image quality as the ingredient for impressive views. Blackened lens edges, anti-reflection threads and rubber eyeguards deliver maximum contrast. Adapter skirts for 2" focusers on larger 1.25" TeleVue Telescope Eyepiece models and rubber grip rings are additional Tele Vue "firsts". Even 2"/1.25" barrel models have an additional feature allowing the 2" extension tube (EBX-2120) to be screwed on, which permits use of 2" TeleVue Eyepiece Filters as well as 1.25". 100% full field visual inspection on TeleVue''s own flat-field test instruments guarantees the performance of every TeleVue Telescope Eyepiece.
The Type-4 TeleVue Telescope Eyepiece models feature about 18mm of eye relief and with the "instajust" eyeguard are best for eyeglass wearers or TeleVue Dioptrx users in their 22, 17, 12mm focal length range.
"You may know there''s a long history of naming telescope eyepieces after their designers: Kellner, Erfle and Plossl, to name a few. In the late 70''s I designed an eyepiece sufficiently radical that I dared attach my name to it. Even today, I must admit a little discomfort when talking about "Nagler" eyepieces.
With TeleVue Telescope Eyepiece "Naglers", my aim is to approach the wide angle perspective of naked eye vision, while maintaining the highest degree of sharpness, contrast, and viewing comfort. The goal is to allow the telescope to virtually "disappear," leaving the impact of "spacewalk" viewing." --Al Nagler
TeleVue 17mm Nagler Type 4 Eyepiece - 2" Features...
- The Type-4 models feature about 18mm of eye relief
- Yields more contrast, reduced pincushion, more true field, and longer eye-relief
- Blackened lens edges, anti-reflection threads and rubber eyeguards deliver maximum contrast
- Adapter skirts for 2" focusers on larger 1.25" models and rubber grip rings
- Click-stop Instadjust eyeguard helps maintain proper eye distance and centration
- Flat-field test instruments guarantees the performance of every Tele Vue eyepiece
TeleVue 17mm Nagler Type 4 Eyepiece - 2" Specifications...
Focal Length (mm): 17
Barrel Size (in.): 2"
Apparent Field of View (deg.): 82
Eye Relief (mm): 17
Weight (lb / oz): 1.60 / 25.6
Field Stop (mm): 24.3
Warranty: Limited LifetimeTeleVue Product Number: EN4-17.0