Brightwell Dayspring 7 mm wide-field eyepiece

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. 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. With a twist-up eyecup, you can raise or lower the cup in steps to match your eye relief needs.

The silver anodized body is easy to find in a dark accessory case and wipes clean after dewy nights. The 2023 edition uses the same lens design as later years, with small differences in the grip pattern. 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 rubber eyecup
• Top and bottom dust caps
• Padded storage case

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.