Choosing Binoculars for Nature Study

equipment_binoculars — Choosing Binoculars and Naturalist equipment: My sturdy Zeiss binoculars, 7x42s

For the naturalist, binoculars are the most essential equipment besides keeping a nature journal.

I use them in my backyard to get a good look at birds at my feeders. I have found them useful in watching butterflies, just ten feet away.

With a good pair of binoculars with close focusing, you can watch:

birds
butterflies
dragonflies
spiders
large mammals
small mammals
dangerous animals
leaves on tall trees
flowers in inaccessible places
objects not easily seen from marked trails
and birds of prey flying high overhead

equipment_binoculars_IMG_4074 — Choosing Binoculars and Naturalist equipment: A good mid-priced set of binoculars. Here are Pentas 8X43s like mine on Amazon.com.

Binoculars Features and What They Mean

Viewing power is stated by magnification times objective size.

An example is 8X42. This translates to 8 times magnification and a 42 millimeter diameter objective lens. The image is magnified 8 times the size seen by the naked eye. A bird that is eighty feet away seems just 10 feet away.

The objective is the large front end. The larger the glass end, the more light is let in and the brighter and sharper the image will appear. This is important in low light situations such as in woodlands or at dusk.

Donna watching hawk migration on Hawk Mountain.

Features to Choose for Nature Watching

Close Focus is the ability to focus and clearly see an image a short distance away. For watching warblers or butterflies, most people choose close focusing of 6 feet or less. If this is you main type of viewing, try a model with as short a close focus as possible.

My favorite binoculars to use have both distance and close-focusing allow my binoculars to be useful in many situations.

Field of View is how wide a scene of landscape you see through the lens. The higher the magnification power, the narrower the field of view. Large objectives do not increase the field of view. In other words a pair of 7X35 will have a wider field of view than a pair of 7x50s. This is due to eyepiece design. The wider the field of view the better the chance of keeping a moving bird in your sights.

Most models that are rubber coated are water-resistant. If your binoculars may possibly be submerged, like during hiking and canoeing, look for waterproof models.

humans_child_young birder — Young Birder.

Points for Eyeglass Wearers

Most models come with adjustable eyepieces for eyeglass wearers. These are eye cups that roll or fold down. These cups work best with moderate near-sighted or far-sightedness. I have monocular vision; one eye is farsighted and one eye is nearsighted. Each of my binocular eye cups adjusts just fine to my eyesight and I don’t have to wear glasses with them.

If you have moderate to severe astigmatism you will probably need to wear your eyeglasses. Trying a pair out is key to comfortable viewing.

Compact Models have:

the same magnification strengths such 7 or 8 times
smaller objective lenses such as 21 or 25 instead of 35 or 42
come in sizes – 7X21, 8X25, 10X25

This is “you-can-carry-them-in your-pocket” size. I have a pair and really like their small size. The limitations aren’t many. The smaller objective may deliver an image not as bright, but in bright daylight that may not matter. Also the field of view may be narrower.

The small size may sound great if you have weakened arm strength but a compact’s small size is affected by hand tremors. Larger models can absorb the tremors and give a steadier image. And your arms are heavier that your binoculars. It is most likely holding up your arms is what makes your hands shake.

This size is good for their portable size and backyard viewing.

Full-sized Models Have:

have magnification strengths such as 7 or 8 times
objective sizes such as 35 to 50 mm in diameter
comes in sizes such as 7X35, 8X35 or 7X42

Full-size models can are very versatile. These models can offer the widest range of viewing in different situations. My Pentax 8X43s have served me well observing migrating birds of prey on Hawk Mountain and migrating spring warblers in nearby woodlands. Similar Pentax 8×43

Large-size High Powered Models Have:

10x power or higher magnification
objective sizes are 35 to 50 mm diameter
come in sizes such as 10X30, 10X42, 12X50

The bigger “binocs”, the heavier they are. These heavier models may need extra support such as a tripod or wide neck strap. The 10x magnification is probably the largest a person can hold without tripod support. The extra magnification revels more details and can see longer distances. These are good for watching raptors, waterfowl and large animals.

humans_young birders at Tinicum — Young Birders at John Heinz NWR at Tinicum, Philadelphia, PA

Choosing a Good Pair of Binoculars

I can almost guarantee that one year after you buy your binoculars new models with fancier features will come on the market. I learned the hard way after buying an expensive pair of binoculars. It was before close focusing was perfected. I can’t use these expensive, heavy gems to watch butterflies and dragonflies several feet away. But, they are still exceptionally good for watching birds at a distance.

My latest pair is an excellent moderate-priced of binoculars. I choose Pentax 8x43s and I am very pleased with them. Here are Pentas 8X43s like mine on Amazon.com (Affiliate link. See FAQs: Buying from this Site).

There are no “perfect” binoculars. Choose a model within your budget. Set your priorities. Choose your two most frequent viewing situations and buy for them, you may not do every type of viewing.

Birding magazines often test models and print articles a couple times a year. Look in Birder’s World, Wild Bird and Bird Watcher’s Digest. Consumer Reports publishes product reviews. Optical suppliers also have online articles on the ins and outs of choosing suitable binoculars. Christophers Ltd. has several pages on choosing binoculars.

An website that reviews and sells binoculars is RedstartBirding.com. And of course Amazon.com.

Reading the articles will help you to narrow down your choices. If you join in on local birding trips hosted by environmental centers or birding groups, you’ll be ask the other birders what they recommend. You may even be able to try out a pair.