As with almost everything in life and especially in the world of optics, there is no such thing as the perfect birding binocular and one size will not fit all, it is all about compromises and deciding what features are most important to you and your particular needs.
The most common configuration for a good all round full size birding binocular is an 8x42 (8x magnification with 42mm objective lenses) as this ensures that you get a nice wide field of view, but with a magnification that is powerful enough to get a good view of the bird. But this may not be the ideal setup for everyone.
So rather than me or anyone else telling you what binoculars to get, I feel that it is important for you to decide what your specific needs and wants are and then make an informed choice, by narrowing the list down to the optics that have all or as many as possible of the features that you need.
Not all birding is the same and there are many different situations and places where you can go birdwatching. For example if you mostly observe birds over long distances in wide open areas, I'm thinking of places like at the coast or by a lake for example, your ideal binocular will be different from someone who mostly does their birding in thickly forested areas. So it is important to decide if you need a specific niche within birding or if you are after a good general birding binocular that will serve you well in a variety situations.
Ways to watch birds
Here again, it is important to think about how you mostly go about your birding: if you do most of your birding at home in your garden, a light compact binocular may not be as important to you as someone who goes on long hikes carrying loads of other equipment like cameras or even spotting scopes as well. Once again, you may be the type of person that does a bit of everything and will therefore be looking for a good all-rounder.
So now that you've had a think about what your specific needs and wants are - I'll go over the main specifications and features on a pair of binoculars in relation to birding and point out what areas they are beneficial and if they have any negative effects...
Most people who are new to the world of optics assume that the more powerful the magnification, the better the pair of binoculars. This, in most situations, is not the case and for most birding situations, magnifications of between 7x and 12x should be fine as there are some negatives to having very powerful magnifications.
The two biggest drawbacks to using very powerful binoculars are that it makes it really difficult to keep the image that you are looking at through the optics still as any slight movement is magnified more and more by larger magnifications. Your field of view also reduces as the magnifications go up. A small field of view will make it much more difficult to spot birds, especially faster moving ones. A wide field of view will also help when you are scanning over large areas. Other drawbacks to more powerful magnifications include increased weight as thicker glass is needed and the brightness of the image produced decreases.
Unless you have unsteady hands, image shake only really becomes a problem when you start using magnifications of more than 15x. You can solve the image shake problem in a few ways: attach your binoculars to a tripod, window clamp or hide clamp or you could use a pair of image stabilised binoculars, most of which use electronics to help stabilize the view.
So look for a more powerful magnification when you mostly view birds at large distances and where the field of view is not that important: places with wide open areas like at the coast or at lakes and dams.
The most commonly used magnification for general birdwatching binoculars is 8x and occasionally 7x. For those who want a little more power 10x is a good choice.
Field of view
The field of view is the horizontal width of the image you can see while looking through the binoculars at a certain distance. It is usually represented as a number of feet at one thousand yards of distance or meters, one thousand meters away. It is also sometimes expressed as an angle.
In general, as you increase the magnification on a pair of binoculars your field of view (the width of the image that you see through your optics) reduces.
In most birding situations a wider field of view is more important than a powerful magnification as it makes it easier to scan wide areas looking for birds and it is easier to find and follow fast moving birds at fairly close distances.
A downside to most binoculars with a very wide field of view is that you lose some of the pinpoint detail, but this is minimal. What I generally do is choose the magnification I am after and then look for the binoculars with the widest field of view within that subset.
As a guide, the best 8x binoculars have a field of view of over 399ft at 1000 yards / 133m at 1000m (7.6°)
Image Brightness & Quality
As the beautiful dawn chorus reminds me every day, most birds are most active in the early mornings and late afternoons. Unfortunately at this time of day, the light is usually pretty poor and that is why if you do a lot of your birding in poor light conditions, it is important to get a pair of binoculars that not only gather as much light as possible, but then transmit as much of that light to your eyes as possible.
Other situations where image brightness is vital include if you do most of your birding in forested areas or even jungles in some parts of the world, where most of the light is blocked out by the trees.
Objective lens diameter
To collect as much light as possible you need binoculars with large objective lenses (the big lens at the front end of the binocular), the problems associated with larger objective lenses are that your binoculars will then become progressively bigger and heavier and larger lenses tend to be more expensive to make.
So if you do all or most of your birding from home, the size of binocular may not be that important so you may wish to look at full size binoculars with objective lenses of about 42mm or larger.
If, however, you need to take your binoculars travelling with you, or you want a light small pair for hiking then a smaller objective lens may be more important than the extra brightness that you would get from a larger pair. Compact binoculars tend to have objectives of less than 28mm.
If you want the best of both worlds, an alternative is to get a mid-sized binocular (objectives of around 30 to 36mm) which are small enough for most people to easily carry around, yet offer slightly better light gathering ability than a full compact pair would.
Lenses, prisms & their coatings
No matter what size objective lens you choose, the next step is to get as much of that potential light to your eyes as possible and here is where you find the biggest differences between cheap and more expensive binoculars. The quality of the lenses, the prisms and their coatings really make a big difference not only to the brightness of the image, but the quality of it as well and indeed the cost.
It's important to be able to cut through and understand the marketing jargon to fully understand what quality of lenses, prisms and coatings have been used so you can make more of an informed decision...
Features to look out for:
- BAK-4 Prisms - These are made of superior optical glass that produce clearer images and is what you want in your binoculars.
- Extra Low Dispersion Glass (ED Glass) - ED glass prevents chromatic aberration because it concentrates and directs the wavelength of light more effectively to your eyes and generally speaking, the better the aberrations are controlled, the cleaner and brighter the image will appear.
- Field Flattener Lenses - These improve edge sharpness and lower the distortion by minimising curvature of the field aberrations that occur when focusing on the center of the field of view causing the edges to go out of focus or the center to go out of focus when focusing on the edges.
- Fully Multi-Coated - This means that all air to glass surfaces have received multiple layers of anti-reflection coatings as opposed to only Multi-Coated or even just coated lenses.
- Phase Correction Coatings - This is a set of coatings on the prism glass that keeps light in correct color phases. Note: these coatings are only needed on roof prism binoculars and they enhance resolution, contrast, and color fidelity.
Features to avoid:
- Ruby Coatings - Some manufacturers filter red to compensate for poorer-quality optics that do not properly converge the color spectrum. By eliminating red from the spectrum, the optics appear to do a better job of minimising color aberrations, but the view through the binoculars often have an unnatural greenish cast. My advice is to stay well clear of binoculars that have "ruby" coatings.
- BK-7 Prisms - These are usually used in lower priced binoculars. Whilst satisfactory, they are inferior to prisms made from BAK-4 glass.
- Coated or Multi-Coated - Means a single layer or multi-layer of anti-reflection coating on some lens elements (usually the first and last elements). Some manufactures will highlight “Multi -Coated” lenses but make sure that they are Fully Multi-Coated to ensure that all lens elements have received anti-reflection coatings.
I'm not saying that you have to get a pair of binoculars with the best ED glass and all the best coatings available, as they can get really expensive. My advice would be to go with the best that you can afford and that means selecting the binoculars with as many positive elements and as few of the negative ones as you can within your price range and hopefully in this way you will find the right birding binocular for your specific needs.
About the author
Jason currently lives in the UK, but was born and grew up in Zimbabwe. He is passionate about wildlife, travel and is a keen bird and wildlife photographer. He is a qualified Field Guide (safari guide) and has worked on safari lodges in South Africa. He owns and runs the Safari Holiday Guide and the Best Binocular Reviews website that has a section on Birdwatching Binoculars - they do their best to keep him behind a desk most of the time, but he is always looking for an excuse to get back into the bush.