Quillon Halyard 5 mm wide-field eyepiece

Specifications

Description

The Halyard 5 mm is a five-element wide-field eyepiece with a 60-degree apparent field and a 1.25 in barrel. At this focal length it works as a high-power eyepiece for close double stars, planetary detail, and the dense cores of globular clusters. In a 1,200 mm telescope it gives 240x with a true field of about 0.24 degrees, and in a 2,032 mm Schmidt-Cassegrain it gives 406x with a true field of about 0.14 degrees. Start at lower power and centre the target before you switch to this eyepiece.

The 5.0 mm field stop sets the true field in every telescope. Because the apparent field is 60 degrees, the eyepiece keeps the image wide at high power, so you can hold a target near the centre of the view for longer. The five elements are fully multi-coated to reduce internal reflections in the high-power beam. Edge sharpness depends on the telescope, and faster reflectors will show more softening toward the edge than slower refractors.

The eye relief of 10 mm is short for an eyepiece of this design. Observers who wear glasses may need to remove them to see the full field, and the rubber eyecup gives limited support against the brow. The barrel is threaded for standard 1.25 in filters. Combined with a Barlow lens, this eyepiece reaches high magnifications, so check image steadiness before using the combination. At 95 g, the eyepiece balances well on a focuser and a diagonal of moderate weight.

About this configuration

All configurations of the Quillon Halyard 5 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.

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 Halyard 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 pouch
• 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).
• Eye relief of 10 mm suits observers without glasses; glasses wearers may need to remove them.