Porro Prism Binoculars

If you picture a traditional pair of binoculars, there is a good chance you are thinking of a Porro prism design.

Unlike other modern binoculars, where the barrels run in a straight line, Porro prism binoculars have a distinctive shape. The objective lenses sit wider apart than the eyepieces. This gives the binocular its familiar stepped appearance.

What Are Porro Prism Binoculars?

Porro prism binoculars use a series of offset prisms to direct light through the binocular before it reaches your eyes. This creates a wider body shape than a roof prism binocular. The light follows a zigzag path instead of travelling in a straight line. The design has been around for well over a century and remains common in many binocular ranges today.

Why Do Some People Prefer Porro Prism Binoculars?

One reason is the viewing experience. Because the objective lenses are spaced further apart, Porro prism binoculars often provide a stronger sense of depth. 

This can make landscapes and wildlife appear more three dimensional compared to some roof prism designs. Users also appreciate the wide, immersive view that Porro prism binoculars have.

Are Porro Prism Binoculars Better Value?

It is possible to find a Porro prism binocular with very good optical performance at a lower price than a comparable roof prism model. This is one reason why they remain popular with beginners and budget conscious buyers. That does not mean they are always cheaper but they are often known for offering strong value for money.

What Are They Commonly Used For?

Porro prism binoculars are used for a wide range of activities.

Birdwatching, wildlife observation and stargazing are all common uses. Their bright image and good sense of depth can make them enjoyable to use in a variety of outdoor settings.