Tele Vue Nagler T7 14mm 82° Eyepiece - 1.25"

The 82° Nagler Apparent Field

The defining feature of this eyepiece is its 82° apparent field of view, a design pioneered by Al Nagler to replicate the immersive perspective of looking through a spacecraft window. This expansive field eliminates the feeling of looking *through* an instrument, instead creating a sense that you are suspended in space. The 14mm focal length provides a useful medium magnification that makes this immersive effect accessible in a wide variety of telescopes.

Seven-Element Optical System with Full Multi-Coatings

Achieving a sharp, high-contrast 82° field requires a sophisticated optical design. The Nagler T7 14mm uses a seven-element layout that corrects for aberrations like astigmatism and field curvature, ensuring star points remain sharp across the vast majority of the view. Every glass-to-air surface receives Tele Vue's proprietary multi-coatings, which boosts light transmission to over 95% and minimizes reflections for a bright, high-contrast image.

Internal Baffling and Blackened Lens Edges

Maximizing contrast is not just about coatings. This eyepiece incorporates blackened lens edges and internal anti-reflection surfaces to intercept and absorb off-axis stray light. This meticulous internal light control is what produces the Nagler's signature "black background," which makes faint details in nebulae and galaxies stand out more distinctly against the sky.

Optimized for Fast Telescopes with Paracorr

While the Nagler T7 performs well in any high-quality telescope, its design is specifically optimized to work with the Tele Vue Paracorr Type 2 coma corrector. In fast Newtonian reflectors (f/5 or below), this combination delivers tack-sharp star points from the center of the field right to the edge. This synergy makes it a premier choice for Dobsonian users who want to leverage their large aperture for wide-field deep-sky observation.

Ergonomics and DIOPTRX Compatibility

The eyepiece features a fold-down rubber eyeguard that helps you maintain the correct 12mm eye relief and blocks stray light from your surroundings. For observers with astigmatism, the top of the eyepiece is threaded to accept Tele Vue's DIOPTRX correctors. This allows you to dial in your exact prescription, enabling you to observe without wearing glasses and still see the entire 82° field with perfect sharpness.

The View: Resolving M13's Core

In a 10-inch f/5 Dobsonian, the 14mm Nagler provides about 90x magnification, an ideal power for globular clusters. Pointing to the Great Globular Cluster in Hercules, M13, the view is immediately engaging. The cluster doesn't just sit in the field; it fills it, with its outlying stars stretching towards the edges. As your eye settles, the eyepiece's high contrast allows you to resolve countless individual stars deep into the dense core, transforming it from a fuzzy patch into a glittering ball of ancient suns.

Choosing Your Nagler: T7 14mm vs. Other Tele Vue Eyepieces

The Nagler T7 14mm occupies a specific niche in the Tele Vue lineup. Its primary trade-off is its modest 12mm eye relief, which can be tight for eyeglass wearers. Understanding the alternatives helps clarify its purpose.

• vs. Delos 14mm: The Delos offers a smaller 72° field but provides a much more comfortable 20mm of eye relief, making it the better choice for observers who must wear glasses. The Nagler is chosen when the widest possible field of view is the top priority.
• vs. Nagler T6 13mm: A very close sibling, the 13mm T6 is even smaller and lighter. The 14mm T7 offers a slightly different magnification step and optical feel that some observers prefer. The choice often comes down to the specific magnification needs of your telescope collection.