Quillon Marram 20 mm wide-field eyepiece

Specifications

Description

The Marram 20 mm is a five-element wide-field eyepiece with a 60-degree apparent field and a 1.25 in barrel. Its 19.5 mm field stop sets the true field, which is wider than that of a standard 52-degree Plössl at the same focal length. That makes it a practical choice for framing large star clouds and open clusters. It sits between low-power and medium-power eyepieces in most collections.

A 20 mm eyepiece gives 60x in a 1,200 mm Dobsonian, 35x in a 700 mm refractor, and 102x in a 2,032 mm Schmidt-Cassegrain. In the 1,200 mm telescope, the true field is about 1.0 degree, enough to frame most of the Double Cluster at 60x. In the 700 mm refractor, the true field of about 1.7 degrees covers most of the Orion Nebula and its surrounding dust. At 102x in the catadioptric, the true field narrows to about 0.6 degrees, which suits planetary and lunar detail at high power.

The five elements use fully multi-coated glass, and the edges of the lens cells are blackened to reduce internal reflections. Images stay sharp across most of the field in telescopes slower than about f/6, with some softening near the edge in fast Newtonians at f/4 to f/5. With 15 mm of eye relief, the eyepiece suits many observers who wear glasses, and the fold-down rubber eyecup blocks stray light when raised and gives room for glasses when lowered.

The 1.25 in barrel is threaded for standard 1.25 in filters and weighs 180 g, so it is light enough for most focusers without added support. The 19.5 mm field stop stays inside the 27.5 mm limit for 1.25 in barrels, so the full field reaches your eye in standard focusers and diagonals. Keep the top and bottom caps on when the eyepiece is not in use to protect the lenses from dust and fingerprints.

About this configuration

This listing covers one configuration of the Quillon Marram 20 mm wide-field eyepiece, defined by its case, eyecup, finish, and edition year. 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 black body with a color ring lets you tell focal lengths apart quickly under a red flashlight. 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
• Padded storage sleeve

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 fast Newtonians.