Eyepiece Beta Classic Ortho 10mm 1.25 inch — orthoscopic telescope eyepiece, 10 mm focal length, 1.25-inch barrel

Beta Classic Ortho 10mm 1.25" is an orthoscopic telescope eyepiece designed for 1.25-inch focusers with a 10 mm focal length. The eyepiece provides a narrow, high-contrast field of view with sharp edge-to-edge performance and low optical aberrations, making it suitable for detailed visual work at medium to high magnifications. Its compact physical format and straightforward mounting make it easy to swap during observing sessions.

Advantages

The orthoscopic optical design yields strong contrast and minimal distortion across the usable field, improving the visibility of fine lunar, planetary, and double-star details. The 10 mm focal length produces appreciable magnification when paired with common amateur telescopes while maintaining comfortable eye relief for visual observing. The 1.25-inch barrel ensures broad compatibility with standard focusers and star-diagonals.

Suitable for

• Planetary and lunar observation where high contrast and sharpness are required
• Double-star splitting and lunar feature studies
• High-magnification views of bright deep-sky objects
• Use with refractors, reflectors, and Schmidt-Cassegrain telescopes that accept 1.25" eyepieces

Key specifications

• Optical type: Orthoscopic eyepiece
• Focal length: 10 mm
• Barrel diameter: 1.25 inches
• Field of view: narrow, high-contrast visual field
• Eye relief: comfortable for direct visual use (typical for orthoscopic design)

How to use

Insert the 1.25" barrel into the telescope focuser or diagonal and secure it with the focuser thumbscrew. Begin with a low-power eyepiece to center the target, then switch to the Beta Classic Ortho 10mm for increased magnification. Adjust the focuser and individual eye position for sharp focus and comfortable eye relief. For planetary work, allow the telescope to reach thermal equilibrium and use steady atmospheric conditions for best results.

Recommendations

For optimal performance, use this eyepiece on bright objects or under stable seeing conditions. Pair with appropriate Barlow lenses or focal reducers only if optical compatibility is confirmed; avoid excessive magnification beyond the telescope's practical limits to maintain image quality.