As an avid natural historian and indeed 'birder' I am never without my binoculars, and having used many models over the last 40 odd years, I have learned what to look for and what works for me.
So for the benefit of those new to the concept of bringing the world closer through glass lenses, I thought I would provide some tips on how to choose well, but without too much 'jargon' and avoiding the physics! There are many websites and articles that go into all the specifics but in brief, what do I go for?
There are 2 main styles, the original ‘stepped’ Porro Prism models, and the straight through, ‘twin barrel’ Roof Prism. I go for full size 'roof prisms', because they are relatively compact. When travelling this is a boon.
You will note 2 numbers printed on the binocular, such as 8 x 42 or 10 x 50 for example. The first number refers to the magnification and the second number to the diameter of the lens at the other end (the 'objective lens'). It might be tempting to go for the highest magnification that you can find, but this is not a good idea
as any hand movement when you are viewing can produce a shaky image. I would say that 8 x magnification is perfect
. The diameter of the objective lens is important as this affects the amount of light being gathered. The larger the diameter, the greater the light, the brighter the image.
Top tip -
divide the diameter of the objective lens with the magnification. Essentially the higher the resulting number, the lighter and brighter the image. A number of 4 or above is recommended, especially in poor light! The quality of the optics will affect the result but you would do well to avoid something like 12 x 20!
You will note that this can be anything from plastic, rubber, leather or even metal. I go for rubber armouring as this takes the bumps and knocks
and assists with grip!
Attached to the strap and fits over the eye pieces. Essential in rainy environments
There are many makes out there, with top end brands such as Leica, Swarovski and Zeiss offering excellent quality. Good brands in the mid and lower cost range include Opticron, Minox, Hawke, Avian and Bushnell.
Top tip -
there are many more brands out there and it is highly recommended that you try before you buy!
While you can check out the models in specialist optic shops, many brands/companies have 'field days' where they demonstrate their wares at locations such as nature reserves.