Baader Hyperion Aspheric 72° 31mm Eyepiece - 1.25"/2"

Aspheric Optics: A 72° Field Designed for the Human Eye

By incorporating aspherical lens surfaces—a technology common in high-end photographic lenses—the Hyperion Aspheric 31mm corrects for distortion and field curvature far more effectively than traditional spherical designs. This results in pinpoint stars from the center to the very edge of the field. The 72° apparent field is a deliberate choice, designed to be fully taken in at a glance without needing to roll your eye to see the edges, providing a comfortable and immersive view.

Phantom Group Coatings: Optimized for Peak Visual Sensitivity

Baader's Phantom Group Coating is a multi-layer broadband anti-reflection system applied to every glass surface. Each coating group is calculated to be most effective where the human eye has its highest sensitivity—in the green portion of the spectrum. Unlike less expensive coatings that produce a strong green reflection, Phantom Group coatings are nearly colorless, ensuring maximum light is transmitted to your eye for a brighter, higher-contrast image with minimal stray light.

Direct-Thread Connectivity for Imaging and SCTs

This eyepiece offers more than just a standard push-fit barrel. On the telescope side, a 2" Schmidt-Cassegrain thread allows the eyepiece to be screwed directly onto the rear cell of an SCT, bypassing the diagonal. This configuration provides an exceptionally secure connection and can yield a wider true field of view than is possible with a standard 2" nosepiece. For astrophotography, the eyepiece features threads on the eye-facing side for direct camera attachment, enabling high-magnification projection imaging.

Stable Viewing: A 72° Field Without 'Nervous' Insight

Many extreme wide-angle eyepieces suffer from a "nervous" or critical eye placement, where a slight shift in position causes the image to black out. The Hyperion Aspheric is engineered for comfortable, stable viewing. The forgiving eye placement makes it an ideal choice for public outreach, educational settings, or anyone who finds fussy eyepieces frustrating, ensuring you and others can consistently enjoy the view.

Baader 31mm Aspheric vs. 80°+ Ultra-Wide Eyepieces

While eyepieces with 80° or wider fields of view are popular, they come with distinct trade-offs that the 72° Aspheric design directly addresses.

• Competitor Advantage (80°+ AFOV): Ultra-wide eyepieces provide a more dramatic "spacewalk" feeling due to their expansive apparent fields.
• Baader Aspheric 31mm Advantage: The 72° field concentrates the available light into a smaller area, resulting in a brighter image, higher contrast, and a better limiting magnitude for seeing faint stars. Furthermore, the entire field is viewable at once, whereas the outer edges of an 80°+ field are often inaccessible without straining your eye.