Image-Stabilized Binoculars for Astronomy

If time is short but you need a good night-sky “fix”, then grab yourself a pair of binoculars and head outside to scan the heavens. Which binoculars are best for stargazing? The answer is, quite simply, a pair of image-stabilized (IS) binoculars. IS binoculars give stunning low power views of the night sky without the dreaded “image shake” of standard binoculars. It’s hard to read a review that doesn’t rave about these advanced optical systems for astronomy or terrestrial use.

Based on technology developed for military surveillance and laser-based weaponry, IS binos are amazing high-tech wonders.  Inside the body of the binoculars, piezoelectric motion sensors detect the pitch and yaw motion caused by the natural shake and jitter of your hands and arms. The sensors feed into a microprocessor that initiates image stabilization by controlling a vari-angle prism – a pair of glass plates joined by flexible bellows. The space between the plates is filled with a silicon-based oil to maximize image deflection to correct for the unwanted motion.

A pair of Canon 10×42 image-stabilized binoculars

The motion sensors work in daylight or total darkness and operate at any orientation, so there are no restrictions on where the binoculars can be pointed… up, down, sideways, anywhere.  You switch on the IS feature by pressing a button.  When you do, the image doesn’t “freeze”, but rather wanders slowly enough for your eye to follow. If your arms shift a little, you’ll still see the image move, but it’s much slower and steadier than without the IS feature.  The IS still works when you sweep across a field of view, although there is a slight hesitation.  It takes a few seconds for the IS to kick in, and perhaps 10-15 seconds for the IS to really get a hold of the motion of your slightly shaking arms.

One drawback: these devices are battery hogs. You can burn through a pair of alkalines in 5 minutes on a cold night. With rechargeables, you might get 2 hours, or longer with warmer temperatures.  Of course, you can turn off the IS feature when you’re not using it.

  Nikon, Canon, and Fujinon, among others, offer some type of image stabilization. Canon models seem to have the widest following among amateur astronomers.

IS binoculars are priced at a serious premium.  In North America, a pair of Canon 10×30’s go for about $400-$500.  A pair of Canon 10×42’s (which are waterproof) go for $1200-$1300, and the 15×50 go for about $1000-$1200.  The more expensive binoculars give you a brighter view of the stars, but they are heavier… about 2-3 lbs, which is hard to hold for a extended period.

Are IS binoculars worth the extra cost?

In a 2006 review of Canon’s 10×42 IS binoculars, Gary Seronik said “These are simply the finest binoculars I have ever used for astronomy”.

I agree.  After investing in a more modest pair of 12×36 Canon’s, I’ve found them extremely useful for quick tours of the night sky.  If you can afford a pair IS binoculars, and if you enjoy quick, convenient, wide-angle views of the night sky, I recommend you pick up a pair.  They’re not a “must-have”, but they’re an “awfully-nice-to-have”.