Bino Blog
We have a lot of conversations with visitors about binoculars and scopes in the RSPB shop and often find that some simple advice can make life so much simpler and bring nature up close in wonderful ways. So, I thought it might be useful to share a few tips and dispel a few myths in this week’s blog.
Firstly, bigger is not always better!
Optics come in a variety of magnifications. For binoculars, the most common are 8 or 10 times magnification, while scopes often offer a zoom lens from 15 or 20 times up to 45 or 60. There are a few other options but as these are the ones you are most likely to see. The first number on optics tells you which magnification they are (8x42 or 10x25 and so on). So, they do not get more ‘powerful’ as they increase in price, they become clearer, brighter and colours become truer; a pair of 8x42 binoculars which cost £100 has the same magnification as an 8x42 costing £2000.
For most bird watchers, an 8 times magnification is great, especially in a woodland environment. You can see a reasonably wide area while increasing the detail very nicely. 10 times magnification makes things a bit bigger but you see a slightly smaller area, so they are better for distance than seeing things relatively nearby. Hence, if you spend a lot of time looking out to sea or across lakes, a 10 times pair may suit you best.
The importance of letting in the light!
The second number on the optics denotes the size of the objective lens (the larger lens). This determines how much light can enter the optics and how bright your image will be. On a 10x42 pair of binoculars, this lens is 42mm, where an 8x25 has a 25mm lens. By dividing the size of the objective lens by that of the magnification you find out how many mm of light will get to your pupil. So, a 10x42 allows 4.2mm or light through and an 8x42 allows 5.25mm through.
More light means we can see more clearly when in the early mornings and evenings and on rainy days as well as in perfect conditions.
This is something to weigh up when buying binoculars. Either a larger objective lens of smaller magnification will make your image brighter. Larger objective lens will also make the optics larger and heavier though, so we need to think about what is comfortable and useable to get the most out of them.
Binoculars or scopes?
Scopes generally have large objective lens, 50, 60 or 80mm, so let in more light than binoculars. They are bigger and heavier though, and of course, you are looking through one eye rather than two.
For viewing nature from a distance, a scope is wonderful. You can focus in on a nest in the cliffs across the lake, or see the sheep grazing on the distant hills, you can bring the detail on the feathers of the smallest birds clearly into view (without the need to get close and disturb them). A scope brings nature closer to you.
Stock photo (not from Lake Vyrnwy!)
You do however, need to find a good point to set up, as a tripod (hide clamp or sometimes a monopod), are needed to provide a steady image. This means you will be carrying quite a lot of kit, so binoculars are often an easier companion on a long walk.
The question to ask yourself is whether you want the ease and flexibility of binoculars or the range and power of a scope. It all depends on how you want to connect with nature and is a very personal choice.
Why are some optics £100 and others thousands if they are not always more powerful?
The price of optics varies hugely depending on a number of factors. The first is quality of lenses. Most RSPB binoculars have either BaK-4 prisms or ED lenses, the better the lens the clearer the view.
Most RSPB binoculars are roof prism binoculars (modern, straight binoculars with lenses parallel to each other) but we do still supply the porro-prism type for those who like the traditional style of binoculars. There are pros and cons between the two.
Next, coatings are important. They make the colours truer and image clearer and repel rain and dirt. Having more coatings will help but will also increase the price.
If you would like more info or to try a few pairs out, come and have a chat with us in the shop or on an optics demo (1st weekend of each month). The best advice is to always try before you buy, as that is the only way to really tell if they are for you.
The right set of optics can really bring nature alive for you and bring you closer to the birds, plants and wildlife you love.
Jampa King, Membership Development Officer
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