Spotting scope vs binoculars: which power for which job

The two tools use different power ranges

ZEISS says typical binoculars for free-hand observation feature 7 to 10x magnification. The RSPB shop calls 8x or 10x the best compromise between power and practicality for birdwatching.

A spotting scope starts where that range ends. Audubon lists popular scope zoom eyepieces as 20-40X, 20-60X or 25-50X, and its test scopes zoomed from roughly 15-60x. Audubon adds that an eyepiece of between 20X and 30X will be most effective for birding.

Of the 554 models in the catalog, 42 reach 15x or more. Those are the ones that overlap with the low end of scope power. See best binoculars compared for the full set.

When a scope is the better pick

Audubon says a spotting scope, with its far greater magnification, is the better tool for distant birds such as shorebirds on a mudflat or hawks circling high overhead. Binoculars suit the closer birds.

That split holds for hunting too. If you glass a far hillside from a fixed spot and can set up a tripod, a scope gives you the extra reach. If you move through cover and need to scan quickly, binoculars win. The binoculars for hunting list shows the models built for the second case.

Why higher power needs a stand

Audubon notes that binoculars magnifying an image eight times also magnify the small movements of your hand eight times. The effect grows with power, so a 20X scope shows twice the shake of a 10x pair.

Celestron says a tripod is not required at 8x to 12x but becomes necessary at 15x and higher. The British Astronomical Association puts the line at 10x: anything above it is difficult to hold and should be mounted.

Celestron also advises mounting a spotting scope on a tripod for stability. Its wording is that the greater the magnification, the more pronounced the shakiness will be.

Where high power binoculars sit between them

A 12x50 pair is the common step above the 10x class. Its median field of view is 277 ft, against 336 ft for the 10x42 and 393 ft for the 8x42. You gain reach and lose width.

Weight rises too. The median 12x50 weighs 29.2 oz, against 24.9 oz for the 10x42. Read 12x50 binoculars and 10x42 vs 12x50 for the figures side by side.

The Royal Astronomical Society says large binoculars can be difficult to use without a stand or tripod. It adds that stabilized high power models exist but are expensive. The stabilized binoculars list covers that route.

Mounting binoculars on a tripod

Binoculars can borrow a scope's steadiness. Nikon says a tripod is effective for long observation or at high magnification, and the maker sells tripod adapters.

Vortex states its binocular adapter fits tripod-adaptable binoculars and tripods with a 1/4"-20 socket or thread. The catalog holds 237 tripod-adaptable models. Check the binocular tripod adapters page for the hardware.

Field of view and brightness

A scope narrows the view sharply compared with binoculars. In the catalog the median field of view is 340 ft, and the range runs from 141 to 563 ft. Higher power pushes a model toward the low end.

Light matters as well. The 10x42 has an exit pupil of 4.2 mm and the 12x50 has the same 4.2 mm, so the larger lens buys the extra power without losing brightness. Work out your own pair with the exit pupil calculator.

Choosing for your situation

Pick binoculars at 7 to 10x if you walk, scan and want one hand free. Audubon strongly recommends six, seven or eight times for most uses.

Pick a scope at 20X to 30X if you watch distant subjects from a fixed spot with a tripod. Pick 15x or more in binoculars only if you will mount them. The tripod guide for binoculars covers the setup.