Baader Hyperion 31mm, aspheric eyepieces

Aspherical eyepieces represent a significant advancement in optical technology, mirroring innovations found in the latest camera lenses. These eyepieces employ aspherical lens surfaces to achieve optimal image performance across the entire visual field, all within a compact and lightweight design. This approach allows for fewer glass layers, which, in conjunction with the high-quality Phantom Group multi-coating, delivers bright, high-contrast images comparable to those from much more expensive wide-angle lenses with spherical designs.

The aspherical eyepieces provide a 72° apparent field of view, which is close to the maximum 68° field that the human eye can see in its entirety without needing to shift focus. This feature ensures that the entire star field can be viewed simultaneously, unlike some wide-angle eyepieces that boast fields of 80° or more, which can dilute image brightness and contrast due to their overly large image surfaces.

Additionally, these eyepieces are noted for their exceptional eye relief, which is especially beneficial for public use in observatories and educational settings, where they help guide even inexperienced observers to the optimal viewing position. This is crucial for mobile telescopes where focusing can cause lens tube vibrations.

For photography, aspherical eyepieces are equipped with an M43 thread, allowing direct attachment of all current DSLR camera bodies and CCD cameras, without additional lenses. A variety of adapter threads and transition rings are also available to adjust focus distances for high-resolution documentation of smaller celestial bodies.

Special Features for Projection Photography:

Each aspherical eyepiece has threading on both sides, making it possible to integrate them into an optical light beam for projection systems. A 2” SC thread on the telescope side ensures secure attachment directly to the lens tube of all Schmidt Cassegrain telescopes, offering a larger true visual field compared to traditional wide-angle eyepieces with 2” holders.

The eyepiece is compatible with both 1.25” and 2” receptacles.

Key Advantages:

• High-quality craftsmanship ensures durability and precision.
• Relaxed viewing with excellent eye comfort.
• Large field of view paired with perfect sharpness.
• Excellent color fidelity across the spectrum.
• Dual compatibility with 1.25" and 2" barrels.
• Minimal distortion and low astigmatism.
• No 'kidney bean' effect, thanks to optimal eye relief.
• Baader Phantom Group coating™ features a 7-layer broadband anti-reflection coating that reduces residual reflections effectively across the visible spectrum, especially around 520nm in the green region, where the human eye is most sensitive at night.

This anti-reflection coating is nearly colorless, indicating its efficiency across all visible wavelengths, ensuring minimal light loss to the night-adapted eye and eliminating scattered light interference.

Specifications:

Focal length: 31 mm

Apparent field of view: 72°

Eye relief: 20 mm

Telescope connection: 2"

Optical system coating: Multiple

Adjustable eyecup: Yes (folding)

Optional camera adapter: Yes

Filter thread: Yes

Inert gas charge: No

General:

Series: Hyperion

Type: Eyepiece

Build type: UWA (Ultra Wide Angle)