Apertura Plössl 4mm
A 4mm Apertura Plössl: a dedicated high-power eyepiece for planets, the Moon and tight double stars, from an honest, sharp 52-degree Plössl at the lowest sensible price.
High power. At 4mm this is a dedicated high-power eyepiece for planets, the Moon and tight double stars; it is not meant for framing large deep-sky objects.
What it's best at — and the trade-offs.
One eyepiece. A different job in every scope.
An eyepiece has no magnification of its own — the telescope decides. The same eyepiece becomes 120× and 26′ of sky in a little refractor, or 508× and a tight frame in a long SCT. Here’s what it does across common scopes.
The numbers, in plain English.
The targets this eyepiece was born for.
Where it sits in your eyepiece case.
A good eyepiece collection isn’t a pile of glass — it’s two or three focal lengths that hand off from wide to tight. This is the anchor at the bottom of the ladder: the one you find and frame with. You buy it once, and it stays your low-power eyepiece for life.
What it pairs with.
How it scores, and why.
Judged as a dedicated high-power eyepiece for planets, the Moon and tight double stars, it earns its score on classic four-element plössl optics: crisp and high-contrast on-axis. Tighter eye relief at this focal length is the main thing holding it back. It is honest about being a specialist, not an all-rounder.
Polaris weighs how well the eyepiece does the job it was designed for — optics, immersion, comfort and value — never list price or brand.
An honest fit check.
Full specifications.
Point it at a planet on a steady night and the case makes itself. This is where the Plössl earns its keep.
For a different goal, start here.
Apertura Plössl 6mm
The same optics with more true field, for framing larger objects and finding your way around.
Apertura Plössl 3mm
The same line at higher power, for planets and the smallest deep-sky detail.
Celestron X-Cel LX
A natural alternative at a nearby price point, if you want to compare field and feel before committing.