Build your EYEPIECE COLLECTION

Great eyepieces are crucial to any astronomical setup. Here Tim Jardine arms you with the info you need to choose the best ones to invest in

- Tim Jardine

Many new telescope packages come with a basic eyepiece or two, good enough to help you get started with the hobby and familiarise yourself with your equipment. Plenty of experienced astronomers will hold fond memories of their first view of Jupiter or Saturn through these starter eyepieces. But it doesn't take long until you start wondering... how much better would the view be through a different lens?

It's fair to say, though, that the choices on offer can be bewildering. Especially given the nomenclature: you might hear of Plössls, orthoscopics, radians and Naglers, or even Kellners and Erfles, and find each costing anywhere between £25 to an eye-watering £1,000 plus - which is perhaps more than the telescope itself!

However, if you can decipher all these terms, you should be able to build a well-chosen selection of four or five eyepieces that will provide high-quality views of everything the night sky has to offer for many years to come.

Types of eyepiece

Wide fields of view offer an immersive, but expensive, option

There are a great many types of eyepiece on offer, but essentially, the difference between them is the apparent field of view. This is measured in degrees as seen by the observer. The human eye can see around 180° in the horizontal plane, and so the closer to this an eyepiece gets, the more immersive your viewing experience will be. Generally, the wider the view on offer, the more complicated the eyepiece's design and the higher the price.