Brightwell Dayspring 7 mm wide-field eyepiece, with hard case

Specifications

Description

The Dayspring 7 mm is a five-element wide-field eyepiece with a 60-degree apparent field and a 1.25 in barrel. It gives a wider view than a standard Plössl at the same focal length, which makes it easier to keep a target in view as the telescope tracks across the sky. The barrel is threaded for standard 1.25 in filters. It is a practical choice for a second eyepiece in a set that starts with a longer focal length.

A 7 mm eyepiece gives high power. In a 1,200 mm telescope it produces 171x, and in a 2,032 mm Schmidt-Cassegrain it produces 290x. At that magnification the true field narrows to about 0.35 degrees in the 1,200 mm telescope, or roughly 21 arcminutes, which is about two-thirds of the apparent diameter of the Moon. Use this eyepiece for compact targets such as planetary disks, double stars, and small globular clusters on nights when the air is steady.

The design uses five elements with fully multi-coated lens surfaces and blackened barrel edges to limit internal reflections. The 6.8 mm field stop sets the true field at the focal plane. In telescopes slower than about f/6 the image is sharp across most of the field. In faster telescopes, expect some softening and field curvature toward the edge, particularly in fast Newtonians.

Eye relief is 13 mm, which suits observers who do not wear glasses. Eyeglass wearers may find the eye point tight, so test the eye position before relying on the full field. The rubber eyecup twists up to block stray light and can be removed for a closer eye position. At 165 g, the eyepiece is light enough for most compact focusers and diagonals.

About this configuration

The Brightwell Dayspring 7 mm wide-field eyepiece is offered in several configurations, and the notes below describe what this particular one adds. The hard foam-lined case protects the eyepiece from knocks during travel and stacks neatly with other cases. A hard case keeps the eyepiece safe in a busy accessory box at a star party or an outreach event. The winged eyeguard wraps around the side of your eye and blocks light from nearby houses and streetlights.

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 2023 edition of the Dayspring line, the earliest version that is still listed in the catalog. 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 rubber eyecup
• Top and bottom dust caps
• Padded storage case
• Hard foam-lined 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; softer at the edge in faster telescopes.