Usage Tips

The biggest problem with binoculars, you'll quickly discover, is holding them steady. The constant dancing of the view prevents you from seeing the faintest objects and the finest detail. As a teenager I followed the moons of Jupiter by holding my binoculars against the side of a tree or wedging them between slats of a fence. Lying on your back and resting their weight on the bones below your eyes will reduce the dancing to a wiggle in time with your heartbeat. A pillow under your head can help.

Today there's a high-tech solution to steady hand-held binocular views — even at higher powers. "Image-stabilized" binoculars use sophisticated electromechanical sensors and actuators to move optical elements inside the binocular to counteract the slight shaking of one's hands. The result? A magically steady view. Image-stabilized binoculars are expensive, but many observers find they're worth it. They do, however, eat batteries. (S&T reviewed a variety of models in the July 2000 and April 2006 issues.)

There are, of course, more conventional ways of steadying the view. Many binoculars can be attached to a photographic tripod with an adapter. This holds them perfectly still for near-horizontal viewing, but you can't get underneath a tripod to look up. A number of special binocular mounts for astronomers are advertised in Sky & Telescope. A half dozen were reviewed in the June 1993 issue, with a further selection in June 2000. These mounts tend to be a bit large and expensive, but the best of them work extremely well.

Short of buying a binocular mount, the usual way of coping with the shakes is to observe from a reclining lawn chair that has arms. By resting both elbows on the chair arms and the eyepieces against your face, the dancing is greatly reduced.

You probably won't be able to set up a tripod over the lawn chair. But if the binoculars are merely attached to a photographic tripod lying across your lap with its legs sticking sideways into the air, the images become much more still. Merely attaching the binoculars to such a large, rigid object is enough to damp down the troublesome rapid jittering. Many amateurs have constructed homemade supports that work well too.

With the glasses held still, their performance will seem at least doubled. Compare the detail visible in solidly mounted 6x30 binoculars (or image-stabilized 10x30s) with hand-held 10x50s.

The comfort provided by the chair is also vital. Some of the most satisfying observations are made at the limit of visibility, where all your powers of concentration are called into play. Any discomfort or strain will interfere with this concentration and blind you to faint detail. This loss is critical. Half of the astronomical objects visible with any instrument — from opera glasses to the Hubble Space Telescope — are within ½ magnitude of the instrument's faint limit. (The reason? By seeing ½ magnitude deeper, you double the volume of space examined.)

Rubber eyecups are also a boon, especially if artificial lights intrude on your observing site.

Charts and notes should be handy, so you can glance back and forth from sky to chart without moving the binoculars. Your lap works fine in a lawn chair, whereas a telescope really requires a separate chart table.

Lastly, start keeping an observing notebook or diary right away — even if you only write down the date, time, observing instrument, and such comments as "Sinus Iridum standing out prominently on Moon's terminator," or "M35 in Gemini a big, dim glow," or "NGC 457 not found." This turns an evening's sightseeing into a permanent collection of observations that will grow in value to you with the passage of time. A plain spiral-bound notebook is ideal for this purpose. The more structured records that some amateurs keep (such as a separate page or file card for each object) are best copied out later, if you want; they are a chore to organize in the dark and constrain your freedom to write down off-the-cuff remarks. It is often these asides — your first bright meteor, an especially clear starry sky after a snowstorm, a night at a memorable site — that often mean the most when you look back on them in years to come.