Halden

Halden Lowmoor 12 mm wide-field eyepiece

12 mm focal length · 50° apparent field · 1.25 in barrel

$259

Catalog preview. Not available for purchase.

Case
No case
Eyecup
Fold-down rubber eyecup
Finish
Titanium gray
Edition
2026 edition

Specifications

Focal length12 mm
Apparent field of view50°
Field stop10.0 mm
Eye relief15 mm
Optical elements5
Barrel1.25 in
Weight150 g
CaseNo case
EyecupFold-down rubber eyecup
FinishTitanium gray
Edition2026 edition

Description

The Lowmoor 12 mm is a five-element wide-field eyepiece with a 50-degree apparent field and a 1.25 in barrel. Its focal length falls in the 10 to 16 mm range, which places it between low-power and medium-power eyepieces. It suits a broad set of telescopes for general observing, from open clusters to large nebulae.

In an 800 mm refractor, a 12 mm eyepiece gives 67x. In a 1,200 mm Dobsonian it gives 100x, and in a 2,032 mm Schmidt-Cassegrain it gives 169x. In the 1,200 mm telescope, the 10 mm field stop sets a true field of about 0.48 degrees. That is enough to frame the core of a globular cluster with room around its edges, or the bright central region of a planetary nebula at a moderate scale.

The design uses five elements with fully multi-coated surfaces and blackened edges to reduce internal reflections. In telescopes slower than about f/6, stars remain sharp across the central two-thirds of the field. In faster systems you may notice some softening toward the edge, so judge the outer field in your own telescope before relying on it for wide mosaics. Its wide field and moderate magnification also make it useful for finding objects before you switch to a higher-power eyepiece.

The 15 mm of eye relief suits most observers, including those who wear glasses. The rubber eyecup folds down for eyeglass wearers and folds up to block stray light. The barrel is threaded for standard 1.25 in filters. At 150 grams, the eyepiece balances well on lightweight focusers. Keep the dust caps in place when it is not in use to protect the lens surfaces.

About this configuration

All configurations of the Halden Lowmoor 12 mm wide-field eyepiece share the same optical design; the options change the eyecup, the case, and the finish. This configuration comes without a case, which suits observers who keep their eyepieces in a shared foam box. No case is included, so the eyepiece ships in a simple box with its two dust caps fitted. A fold-down eyecup is simple and has no moving parts that can loosen in cold weather.

The titanium gray finish has a hard anodized layer that resists wear from repeated insertion into focusers. This is the 2026 edition, the most recent version of the Lowmoor line in the catalog. To find the magnification, divide the focal length of your telescope by the eyepiece focal length in the specifications.

What's in the box

  • Eyepiece with fold-down rubber eyecup
  • Top and bottom dust caps
  • Padded storage pouch

Compatibility notes

  • Fits any 1.25 in focuser, diagonal, or Barlow lens.
  • The barrel accepts standard 1.25 in filters (M28.5 x 0.6 thread).
  • Sharp across the central field at f/6 and slower; softer at the edge in faster telescopes.