ERGONOMICS - Eye Relief

from

Midpriced Binoculars Round Up

by Michael and Diane Porter

Dan testing We evaluated 56 mid-priced binoculars for Bird Watcher's Digest in the summer of 2007.

If you don't wear glasses, eye relief probably won't matter to you a bit. But if you do wear glasses, then binoculars with long eye relief matter a whole lot.

Eye Relief

For every binocular, there is an optimal distance between your eye and the eyepiece. That distance is called eye relief. If your eye is too close to or too far from the eyepiece, you can't see the whole picture: part of it is blacked out.

The challenge for eyeglass wearers is to choose a binocular whose eye relief is long enough to accommodate the glasses. Otherwise, your glasses don't allow your eyes to get close enough to the eyepiece, and you can't see the whole picture.

You lose the outer edge of the image, like the picture of left. What you want is the whole image, like the picture at right.

Bad eye relief Good eye relief

A few years ago, it was difficult to find a binocular with eye relief sufficient for eyeglass wearers. But binoculars have come a long way on that score. Most manufacturers seem to have realized that people with corrected vision make up a significant portion of the binocular market. Most of the binoculars we looked at work well with eyeglasses.

For the eye relief column on the chart, we relied on the numbers published by the manufacturers. If you wear glasses, a good starting place is to consider binoculars with a listed eye relief of at least 16mm.

However, methods of measuring eye relief vary from manufacturer to manufacturer, so you can't rely entirely on the published eye relief figures. Oddly, Leica seems to grade their binoculars' eye relief especially hard. We found that the Leica Ultravid Compacts had excellent eye relief for glasses wearers, despite published eye relief of only 15mm.

Our team especially appreciated the eyecups on the Pentax DCF SP, with its 3-stage indents. The eye relief of the 8x43 model we studied, published as 22mm, is generous enough even for a person whose glasses are large and ride far from the eye. But the 3-stage indents allow a person with closer-fitting glasses to dial an appropriate degree of eye relief.

Other binoculars with particularly long eye relief include the Celestron Regal LX 8x42, The Alpen Models 493 and 496, and the Vortex Viper 8x42. Binoculars such as these, with eye relief of 20mm or more, are good candidates for anyone who has trouble getting the whole picture while wearing glasses.

Another binocular with surprising good eye relief is the Celestron Noble 8x32. We did not include it in the Bird Watcher's Digest Round Up because the price is below the $300 - $800 range of the article. But it's a good binocular, compact and light weight, and get it works exceptionally well for a person who wears glasses.

The safest practice for anyone looking for a new binocular, of course, especially if you wear glasses, is to try 'em before you buy 'em

More about ERGONOMICS:

OPTICAL QUALITY

THE MAIN CHART

THE WARRANTIES CHART

BINOCULARS OF PARTICULAR NOTE

This article appears as part of the Midpriced Binoculars Round Up in the November, 2007, issue of Bird Watcher's Digest.