Omegon AC 90/1000 EQ-2 Refractor Telescope

Omegon AC 90/1000 EQ-2 – a classic refractor for the Moon and planets

The Omegon AC 90/1000 EQ-2 is a classic beginner telescope for visual astronomy. Its 90 mm objective gathers plenty of light for a compact refractor, while the 1000 mm focal length is especially suited to observing the Moon and planets. The manual equatorial EQ-2 mount lets you follow a celestial object with a slow-motion control after aligning the polar axis.

Optics and observing targets

This achromatic refractor has a closed optical tube that needs little routine maintenance and does not require regular primary-mirror collimation. At f/11.1, its relatively long focal ratio supports comfortable views of bright objects and reduces chromatic aberration compared with short-focus achromats, although it does not eliminate it. A fine colour fringe may still be visible around very bright objects at high magnification.

The Moon is a rewarding target: craters, mountain ranges and shadows along the terminator change with the lunar phases. Jupiter and its four large moons, its most prominent cloud bands, and Saturn with its rings are also suitable targets. Under a dark sky, bright star clusters and some larger, luminous nebulae become accessible. Faint galaxies and fine deep-sky detail remain limited by the 90 mm aperture.

Eyepieces, Barlow lens and magnification

The set includes 25 mm and 6.3 mm eyepieces, giving magnifications of about 40× and 159×. The 25 mm eyepiece helps locate objects and provides a wider field; the 6.3 mm eyepiece brings the Moon and planets closer. The supplied 2× Barlow lens doubles an eyepiece’s calculated magnification. More magnification is not automatically better: atmospheric seeing, contrast and mount stability determine which details are actually visible. Omegon lists 180× as the maximum useful magnification.

Equatorial EQ-2 mount

An equatorial mount is first aligned with the celestial pole. The telescope can then follow the apparent motion of the sky along the right-ascension axis; slow-motion controls help centre and track an object. This setup takes a little more explanation than an alt-azimuth mount, but becomes useful at higher magnifications. The EQ-2 is manual and has no GoTo system or motor drive. The aluminium tripod includes an accessory tray for the telescope and accessories.

Included equipment and image orientation

The set includes the 90/1000 mm optical tube, EQ-2 mount with aluminium tripod and accessory tray, red-dot finder, 1.25-inch diagonal mirror, 25 mm and 6.3 mm eyepieces, and a 2× Barlow lens. The diagonal redirects the light path for comfortable viewing and gives an upright but laterally reversed image. For a fully upright and correctly oriented image during terrestrial observing, an optional Amici prism is required.

Buying advice

The AC 90/1000 EQ-2 suits beginners who mainly want to observe the Moon and bright planets and are willing to learn how to align an equatorial mount. Its long focal length works particularly well for medium and higher magnifications; the set already includes two eyepieces and a Barlow lens. The enclosed refractor is also a good choice if you prefer an optical system that does not need routine mirror collimation.

If your main interest is wide fields or large star clusters, a shorter focal length gives a more spacious view. A substantially larger aperture is preferable for faint galaxies and nebulae. The EQ-2 is intended for visual use; this manually tracked set is not designed for long-exposure astrophotography. Allow a little time to learn the equatorial setup; once aligned, the right-ascension slow-motion control makes it easy to keep an object in view.

Technical specifications