ERGONOMICS - Focus Knob

from

Midpriced Binoculars Round Up

by Michael and Diane Porter

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

Here we discuss a characteristic that subtly determines how we feel about a binocular the moment we pick it up — before we even look through it — the focus knob.

Focus Knob

Ergonomic quality in a binocular is conveyed by the focus knob. If it turns smoothly, with even resistance throughout its range, you feel confident in the engineering quality of the instrument. A focus knob with slack doesn't feel right, and it doesn't give you immediate, accurate focusing. Our testers rated each binocular on the perceived quality of its focus knob. The results are displayed in the chart.

Most birders also like a focus wheel that goes quickly from near focus to infinity. If you have to turn and turn the wheel, the flying merlin will be long gone before you roll the knob away from the sparrow in the bush. On the other hand, too fast a focus makes a binocular hard to focus precisely.

A manufacturer that has admirably addressed the challenge of making the focus knob both precise and fast is Minox. The new Minox HG series binoculars (see review) go from close-up to infinity in less than one full turn of the focus wheel.

Up-close focusing is fast, and distance focusing is precise. Going a step further, Minox put a distance scale on the focus knob, turning it into a range finder.

We love this feature, because we often would like to make a note of the viewing distance from a bird, and the Minox GH focus wheel lets us read the distance at a glance.

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.