Brightwell Dayspring 20 mm wide-field eyepiece, with soft pouch

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

The Brightwell Dayspring 20 mm wide-field eyepiece is offered in several configurations, and the notes below describe what this particular one adds. The soft pouch keeps dust off the eyepiece and fits in a jacket pocket during a session. A soft pouch protects the lenses from scratches when you carry the eyepiece between the car and the telescope. The fold-down rubber eyecup blocks stray light, and you can fold it back if you observe with glasses.

A color ring near the top of the body marks the focal length, which helps when you swap eyepieces in the dark. This is the 2025 edition, which added a safety groove to the barrel and a firmer eyecup detent. Check the barrel size in the specifications against your focuser or star diagonal before you choose a configuration.

What's in the box

• Eyepiece with fold-down rubber eyecup
• Top and bottom dust caps
• Plastic storage case
• Soft padded 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 most of the field at f/6 and slower; stars elongate toward the edge in faster Newtonians.