Concept The Nagler Type 7 series was developed as a natural extension of our highly regarded, 85°, limited edition Apollo 11 eyepiece. However, the series can also be thought of as an extension of the long eye relief Nagler Type 4 concept. With the all-new Type 7 design layout, we achieved our goal of Apollo 11-like performance across a series of focal lengths that are eyeglass friendly.
Design Goals The design goal was simple. The performance of each of the Type 7 focal lengths must equal or exceed that of the Apollo 11 eyepiece in the areas of full-field sharpness, contrast, distortion correction, eye relief, and pupil comfort, but across an 82° apparent field of view instead of 85°.
Design Details If you have been waiting for a Nagler series for eyeglass wearers, the Type 7 is it. Combining the expansive 82° apparent field of view with 19 mm of eyeglass friendly eye relief, and large eyelens, the Nagler Type 7s give a new dimension to the "spacewalk" viewing effect. An easily adjustable, locking eye-guard is included for those who don't wear eyeglasses. It helps to correctly position your eye to the exit pupil so you don't get too close to the eyelens, as well as blocks contrast-robbing stray light from interfering with the view. Speaking of which, of course we've applied all the optical coating and baffling features Tele Vue eyepieces are known to maximize contrast and complement the fully corrected field; revealing beautifully natural star colors with pinpoint sharpness. The optical layout affords unrivalled parfocality throughout the four focal lengths and even between 1¼" and 2" modes when used with the Tele Vue Hi-Hat 1¼" and 2" adapter (ASF-8125). The Type 7 series is also parfocal with all other 1¼" Tele Vue eyepieces (except 40 mm Plössl) when those eyepieces are used in the Tele Vue Hi-Hat 1¼" and 2" adapter (ASF-8125). Available in focal lengths of 5.5, 9, 14, and 19-mm, the Type 7s complement the 22-mm Type 4 and 31 mm Type 5 as eyeglass friendly Naglers.
The Nagler Type 7 models all weight 19 to 21 oz / 540 to 590 gm.
Why Are There 4 Types of Naglers?
To achieve various features requires different design tradeoffs and thus the different types of Nagler eyepieces. The largest possible true fields of view for an 82°' apparent field of view in both 2" and 1¼" formats are achieved with the Nagler Type 5 series, with focal lengths of 31 and 16 mm
Compact size in medium to short focal lengths is achieved with the Nagler Type 6, available in focal lengths of 13, 11, 9, 7, 5, and 3.5 mm.
To achieve eyeglass friendly eye relief without excessively large and heavy designs requires the other two Nagler types. The 22mm Type 4 and 19, 14, 9, 5.5 mm Type 7 with their long eye relief feature adjustable height eyeguards and are best for eyeglass wearers or Dioptrx™ users.
Specifications
| Focal Length (mm) | 9 |
| Barrel Size (in.) | 2" & 1¼" |
| Apparent Field of View (deg.) | 82 |
| Eye Relief (mm) | 19 |
| Weight (lb / oz) | 1.21 / 19.4 |
| Field Stop (mm) | 13 |
