Q. I'm thinking about buying some binoculars this spring. Which kind do you recommend for beginning birders and what do all the numbers mean like 8x40?

A. Picking out the right binoculars can be a little daunting, there are so many aspects to consider. For example, big binoculars are nicer to look through compared to smaller ones, but big ones are bigger (obviously) and heavier. So do you choose big with better viewing or smaller and more convenient and portable?

Let's start with the numbers first. The numbers describe the basic parameters of the binocular, but they tell you nothing about quality. The first number is the magnification so a pair of 8x40 binoculars has a magnification of 8. In other words, objects will appear 8 times larger (or closer) compared to the naked eye. Magnifications usually range from 7 to 10 power. It is difficult to hand hold any binoculars greater than 10x and should be avoided. Higher power binoculars are harder to hold steady so if you shake at all consider lower power binoculars. If your hands shake quite a bit, there are stabilized binoculars on the market. The second number tells you how large the diameter of the objective lens (the big one) is in millimeters. So an 8x40 binocular has objective lenses that are 40mm in diameter. The larger this number is the more light the binoculars will collect and the larger and heavier the binoculars will be. Standard binoculars usually have objective lenses that are 35-42mm in diameter. Compact pairs range from 24-27mm. You can find 8x40 binoculars that cost $20 and you can find 8x40 binoculars that cost $2000. So what's the difference?

The quality (and price) of binoculars comes from the kind of glass used and the quality and quantity of coatings the manufacturer puts on all the glass surfaces within the binoculars. Binoculars may look like they only have one eyepiece and one objective lens, but there are many glass pieces inside. Usually binoculars have two prisms, eyepieces with 3-5 lenses and objectives with 3 pieces in each side of the binoculars. Coatings on the glass surfaces reduce reflections so the binoculars transmit more light into your eye and give you a better view. Pairs that say they are multi coated are good and fully multi coated are better. If a pair claims fully multi coated that means every glass surface within the binoculars has multiple coatings on them.

The bottom line is when you look through a pair of binoculars the image should "pop". You should say 'these are great'. If you don't get that feeling it's because the image is dark or fuzzy. It is possible to get a really nice pair of binoculars for not too much money. Binoculars less than $100 are often not much good. As with many things, there are some big differences in binoculars in the $100-$400 range. After that, you start paying a lot for little improvements. Sometimes it's hard to tell the difference between a $500 and a $2000 pair of binoculars. Leave those pairs for when you really get into birding.

This answer has only scratched to surface of possible things to consider. Other important considerations might be eye relief, field of view, waterproof, interpupilary distance, eye cup style, and porro vs roof just to name a few. I usually suggest to people that they consider a standard size pair (i.e. with objective lenses 35-42mm). If you have poor eyes consider lower power brighter binoculars. If you shake consider lower power heavier binoculars. At the Wild Bird Center we often spend quite a bit of time with people selecting binoculars because there is so much to consider. Just take your time and the right choice will be clear (pun intended).