How to choose binoculars

Selecting Binoculars for Birding 

Of all the uses for binoculars, birding is the most demanding. You need the greatest possible image resolution in binoculars that are not too heavy to carry for a few hours at a time, are waterproof, and sturdy enough to resist dropping.

For birding, the primary considerations are:

• The quality of the lenses and the quality of the assembly are the major contributors to resolution and sharpness.

• Ability to focus down to about 5-10 ft. for when that warbler gets really close.

• Ability to focus quickly before the bird flies away. Ideally you should be able to go from close to infinity in one full rotation of the focusing wheel.

• Low weight so that you can hold the binoculars for a few hours if necessary. The maximum weight for comfortable birding is about 25 oz.

• Good balance in your hands, and comfort when pressed up against your eyes.

• Weatherproof features.

Price

Avoid cheap optics. Stay away from the $100 or less price category. Their optical performance will be only passable; their durability won't be very good; they'll likely fog up when used in wet weather; and they won't stay in alignment. At the very minimum plan on spending $200 for binoculars serviceable for birding, but spend more if you can.

Size 8x42 is Recommended. What do the Numbers Mean?

• The first number represents the magnification. This should be at least 7 for birding. Magnification of 10 may be difficult for some birders to hold steady enough.
• The second number (the objective lens size) is the diameter in millimeters of the large inlet lenses. Larger objective lenses let in more light, giving a brighter image.
• The second number should be at least 5 times the first number if you want to see your bird under low light conditions, such as first thing in the morning.

Binocular design requires a compromise between magnification, image brightness, image quality, weight and price. Size 8x42 binoculars provide the best balance of factors for most people (8 times magnification, 42mm light collecting lens). Let’s see how this works. If for instance, you were to increase the magnification (to 10x42) the image will be less bright, the field of view will be less and the image will dance more if your arms are not rock-steady. If for instance, you were to increase the brightness (to 8x50) the extra glass in the wider inlet lens will result in a brighter image but the binoculars will be heavier.

A few other Considerations:

• • If you will use your binoculars with eyeglasses or with sunglasses you need to pay attention to the "Eye Relief" - the distance behind the eyepiece that the image is formed.
• • Avoid zoom binoculars. The image will never be as good as non-zoom binoculars.
• • If possible try the binoculars before buying.
• seriously consider getting a binocular harness. It eliminates neck strain and is only about $20.

Here are some respected brand names:

• Budget Priced ($100 to $200): Bushnell, Audubon

• Medium Priced ($300 to $800): Vortex, Nikon

• Top of the Line (over $1,000): Swarovski, Zeiss

Here are some specific binocular recommendations:

• Bushnell Legend HD: 10x42 ($210)

• Nikon Monarch 5: 8x42 ($250)

• Nikon Monarch 7 ED: 8x42 ($450)

• Vortex Viper HD: 8x42 ($600)

• Vortex Razor HD: 8x42 ($1,200) 

Sources

It is still difficult to find vendors of good binoculars who will ship to Mexico. You can order good optics for US delivery through:

• OpticsPlanet. com

• Amazon.com

When you receive your binoculars:
Don't forget to make the diopter adjustment to compensate for the difference between your two eyes. (Close the right eye and focus in the regular manner; then close the left eye and focus using the diopter adjustment ring.)

References:

The material in this article is based on many sources. The best reference is the Audubon Binocular Guide: https://www.audubon.org/gear/binocular-guide