Omegon AC 80/400 OTA

Omegon AC 80/400 OTA: the standalone wide-field optical tube for custom setups

The Omegon AC 80/400 OTA is a standalone telescope tube without a mount: 80 mm aperture, 400 mm focal length (f/5), and a weight that any mount can handle. Ideal as a wide-field tube on an existing setup, as a spotting scope, or as a lightweight travel tube on a photo tripod.

The achromatic doublet lens with multi-coating combines two types of glass to reduce chromatic aberration. At high magnification, a thin color fringe remains visible around bright objects; this is characteristic of this type of lens and does not interfere with normal use.

Wide field of view, simple operation

The rack-and-pinion focuser with a 1.25-inch connection accepts any standard eyepiece. With a 20 mm eyepiece, you get 20x magnification and a view of entire constellations; star fields, the full lunar disk, and daytime landscapes are the domain of this tube.

Keep the magnification low: at f/5, an achromat will show color fringing above about 80x. This is deliberately a wide-field instrument.

Mix and match

On an altazimuth mount, a photo tripod with a sturdy head, or as a secondary tube alongside a larger telescope: this OTA is the most affordable starting point for a custom setup.

Included

• Achromatic refractor 80/400 with multicoating (optical tube only)
• Rack and pinion focuser with 1.25-inch connection

Featured accessories

The Omegon Mini II Dobson mount (59 euros) instantly turns it into a complete tabletop telescope, and the Omegon Titania 500 tripod (129 euros) is the standing solution. The Omegon 7-21 mm zoom eyepiece (69 euros) provides continuously variable magnification from 19x to 57x, and an Omegon Premium moon filter (19.90 euros) subdues the bright Moon.

Never look at the sun through a telescope without a certified solar filter: this will cause permanent eye damage within a second.

For whom yes, for whom no

For: DIY builders and travelers looking for a lightweight wide-field optical tube for an existing mount or tripod. Not for: anyone who wants a complete out-of-the-box set; the AC 80/400 AZ-3 is the same optical tube with mount, tripod, and accessories. Compare entry-level models via the Choice assistant. Meer Omegon stands on the brand page.

Specifications