Omegon Premium Flatfield 5.5mm 60° Eyepiece (1.25 inch)

Omegon Premium Flatfield 5.5 mm Eyepiece 60° (1.25 inch): flat field of view with ED optics

The Omegon Premium Flatfield 5.5 mm delivers what its name promises: a flat field of view where stars remain point-like even at the edge. The shortest focal length in the series, for planetary detail with a sharp edge.

The series corrects the field curvature that makes most eyepieces blurry at the edge, and the ED lens element keeps the color reproduction pure. Even on fast Newtons around f/5, the edge remains sharp.

Flat field, high contrast

The optical construction with an ED element and multi-layer coating on all air-to-glass transitions delivers a sharp image with high contrast. Objects that drift to the edge retain their shape and sharpness.

Pleasant insight, parfocal series

With an interpupillary distance of 16 mm, you can observe relaxedly, without black shadows if your eye is slightly off-axis. The series is parfocal: changing the focal length requires hardly any refocusing.

The 1.25-inch barrel has filter threads for moon and color filters.

What do you see with 5.5 mm?

On a 150/750 Newtonian, 5.5 mm gives a magnification of 136x, on a telescope with a 1200 mm focal length 218x. Do not exceed a maximum of 2x the aperture in millimeters.

Lunar craters, Saturn's rings, and double stars remain sharp, even when they drift toward the edge.

Featured accessories

The Premium Flatfield series ranges from 5.5 to 25mm and is parfocal: two or three focal lengths form a complete set. An Omegon moon filter (1.25 inch) dims the bright moon image at longer focal lengths.

For whom yes and for whom no

• ✓ Observers with fast telescopes (f/5) who value edge sharpness
• ✓ To see stars as pinpoints to the edge instead of smeared
• ✓ Owners of multiple focal planes in the series: parfocal switching
• For those seeking the widest field of view: the SWA and Redline series offer 70 degrees
• ✗ Smart telescopes without interchangeable eyepieces

Specifications

You can find more accessories for this brand at the Omegon brand page.