Brightwell Dayspring 20 mm wide-field eyepiece

Specifications

Description

The Dayspring 20 mm is a six-element wide-field eyepiece with an 82-degree apparent field and a 1.25 in barrel. Its wide apparent field lets you frame star fields, open clusters, and large nebulae without moving the telescope as often, and it is a useful step between a low-power eyepiece and a higher-power one in a first set.

A 20 mm eyepiece gives 35x in a 700 mm refractor, 60x in a 1,200 mm Dobsonian, and 102x in a 2,032 mm Schmidt-Cassegrain. At 60x in the 1,200 mm telescope, the true field is about 1.4 degrees, enough to hold the Double Cluster in Perseus in a single view with space around it. In the 700 mm refractor, the true field is about 2.3 degrees, which fits the full Pleiades cluster.

The design uses six elements in a wide-field arrangement, with multi-coated lenses and blackened barrel edges to reduce internal reflections. In telescopes slower than about f/6, star images stay round across most of the field. In faster Newtonians, stars may elongate toward the edge of the field.

The 14 mm of eye relief is shorter than that of the low-power eyepieces in most sets, so you need to place your eye close to the lens to see the full field. Observers who wear glasses may need to remove them to reach the full field. The field stop of 25.0 mm sets the true field, and the 185 g weight keeps the eyepiece balanced on most focusers. The barrel accepts standard 1.25 in filters.

About this configuration

All configurations of the Brightwell Dayspring 20 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. The winged eyeguard wraps around the side of your eye and blocks light from nearby houses and streetlights.

Black anodizing is the standard finish of the Dayspring line and matches most focusers. This is the 2026 edition, the most recent version of the Dayspring 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
• Plastic storage case
• Winged rubber eyeguard

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 most of the field at f/6 and slower; stars elongate toward the edge in faster Newtonians.