Telescope Eyepieces with Barlow Lenses
A Barlow lens is a popular tool for magnification in telescopic eyepieces. Economic and effective, telescope eyepieces with Barlow lenses are great for enhancing an image when stargazing.
Named after the astronomer Peter Barlow, these lenses have been around since the eighteenth century and are still a popular tool for enhancing the capabilities of telescopes. A Barlow lens allows you to expand the focal length without needing extra lenses.
How it works
A Barlow lens is a concave shape and can be placed between the lens and the telescope eyepiece to increase the range of magnification. It fits inside the eyepiece for easy use. Just drop it and screw in before connecting the eyepiece. Barlow lenses are a great solution for seeing a bit further.
There are many different strengths of Barlow lens available depending on the focal length you would like. It's commonplace to use a 2x lens for double the magnification though there are other strengths of lens available up to 100x. The extra magnification will allow you to gain amazing views of the moon, planets, the stars and beyond.
Selecting a lens
When you choose a Barlow lens for your telescope it's important to get the correct barrel size so that it fits your eyepiece perfectly. The standard size is one and a quarter inches but this may vary so always check. The right size lens should feel like it was made to measure and screw in securely.
Some Barlow lenses are coated to improve the quality, whilst some are also encased in a metal housing for protection and stability.
Generally, telescopes with Barlow lenses are of a high quality with clear glass optics for a clear, crisp image. There are some less expensive plastic versions available but they may not give you the best image quality.