Free Ground Shipping Available (CONUS Only)
This is a used original 7mm TeleVue Nagler. This has been superseded by the new Type 6, whose complete description is below, and is not completely applicable to this particular eyepiece.
If you're looking for the eyepiece that revolutionized widefield astronomy, look no further - here it is. It is in very good condition: the optics are clear and clean, the barrel has a small scratch that does not effect the views. It comes in its original box, with only the bottom cap - the top cap is missing.
Compare a penny to a half dollar to see the relative size between a 50° and 82° apparent field - almost 3 times the area difference! And while others 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 1¼" models and rubber grip rings are additional Tele Vue "firsts". Even 2"/1¼" barrel models have an additional feature allowing the 2" extension tube (EBX-2120) to be screwed on, which permits use of 2" filters as well as 1¼". 100% full field visual inspection on our own flat-field test instruments guarantees the performance of every Tele Vue eyepiece. Nagler Type 6
The 7-element, Nagler Type 6 design is based on the original patented Nagler design. This new 7-element design update for the short focal length Nagler deserves its own designation. Using different exotic materials, coating processes and design ingenuity, Al has massaged more eye-relief, contrast, and true field of view into the shorter focal length Naglers, while maintaining the absolute sharpness of the originals. Eye-relief is 12mm on each model, and all are sized about the same as the original 7mm! Weight about 0.4 to 0.5 lbs.
Concept: The goal we set designing these new eyepieces was to increase contrast, maintain or increase eye-relief, reduce size and weight, and maintain the sharpness of the originals. They are all parfocal and great with the Bino Vue.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 31, 16mm and Nagler Type-6 with focal lengths of 13, 11, 9, 7, 5, 3.5, 2.5mm.
The Type-5 permits the largest true field possible (31mm has 42mm field stop).
Type-6 models have shorter focal lengths, are parfocal, with similar size and weight, and all with a comfortable 12mm eye relief.
Al Nagler said of the Nagler line, "You may know there's a long history of naming 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 '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."
|Focal Length (mm)||7|
|Barrel Size (in.)||1¼"|
|Apparent Field of View (deg.)||82|
|Eye Relief (mm)||12|
|Weight (lb / oz)||0.50 / 8.0|
|Field Stop (mm)||9.7|