Eyepiece Celestron Omni 9mm 1.25" (MPN 93318) — 9 mm focal length, 1.25-inch barrel

The Celestron Omni 9mm eyepiece with a 1.25-inch barrel is a compact optical accessory designed for visual astronomy. With a 9 mm focal length it delivers higher magnification when inserted into telescopes that accept 1.25" eyepieces. The eyepiece provides a straightforward solution for observing the Moon, planets and other bright celestial objects through standard focusers, offering a balance between magnification and eye relief in a small, lightweight package.

Advantages

This eyepiece is engineered to provide clear, contrasty views at higher magnifications suitable for planetary and lunar details. Its 1.25-inch barrel fits a wide range of amateur and backyard telescopes, enabling straightforward interchangeability with other 1.25" accessories. The compact form factor makes it easy to handle and store, and the optical design is intended to minimise aberrations at the eyepiece plane for improved image sharpness.

Suitable for

• Planetary observation (Jupiter, Saturn, Mars)
• Lunar viewing and lunar surface detail studies
• High-magnification views of bright deep-sky objects
• Use in refractors, reflectors and Schmidt-Cassegrain telescopes with 1.25" focusers
• Field use for amateur and hobby astronomers

Key specifications

• Focal length: 9 mm
• Barrel diameter: 1.25 inches
• Optical purpose: visual astronomy eyepiece for higher magnification
• Form factor: compact, lightweight eyepiece suitable for portable setups
• Compatibility: designed for telescopes accepting 1.25" eyepieces

How to use

Insert the eyepiece into the telescope focuser or diagonal designed for 1.25" barrels and secure it with the focuser's thumbscrew. Start with a low- to medium-power eyepiece to locate the target and then switch to the 9 mm eyepiece for increased magnification. Adjust the telescope focus until the image appears sharp; use slight refocusing to compensate for seeing conditions. If eye relief is limited, position your eye carefully at the exit pupil to obtain the full field of view.

Usage recommendations

For best results, use the 9 mm eyepiece on nights with stable atmospheric seeing and on targets that benefit from higher magnification, such as planets and the Moon. Combine it with a properly collimated telescope and a diagonal for comfortable viewing. Avoid using very high magnification on faint objects where image brightness and detail may be insufficient.