Choosing scopes and binoculars: A beginner’s guide
Buying optics for the first time can be bewildering, but our expert David Chandler will help you focus on finding what’s right for you.
Binoculars and scopes offer fantastically close views of wildlife and will enhance days out for years to come. But with so many products on the market it can be hard to know where to start. You need to consider carefully what you need from your optic, and how easy it will be to use.
How much do they cost?
Prices range from less than £100 to more than £2,000 for binoculars, and less than £150 to nearly £3,000 for scopes. But you can get good optics at much lower prices than the top-range products, and can always buy second-hand. As well as budget, consider what you will be using your optic for. Is it mainly for watching birds and mammals? Do you want to look at insects in detail? How much low-light watching will you do?
What do all of the numbers mean?
An 8x42 pair of binoculars magnifies 8x – so the subject is eight times closer – and has a 42mm objective (light-gathering front lens). A 25–60x 85 scope magnifies from 25x to 60x, and has an 85mm objective. Most wildlife watchers use 8x, 8.5x or 10x binoculars. Bigger magnification isn’t necessarily better, though – the field of view tends to be narrower, and the optic is harder to hold steady.
Scopes can have fixed magnification or zoom eyepieces. A zoom gives you options, but decent ones are expensive. For a fixed magnification, something around 30x is a good choice. If there’s a wide-angle option, go for that.
All things being equal, the bigger the objective lens, the brighter the view. In terms of the objective size, 32mm or 42mm binoculars are popular choices. If you want a smaller, lighter pair, and don’t need low-light performance, compact binoculars with 20–25mm objectives are also worth a look.
Is weight an issue with scopes?
If you want to travel light, you could try a 50mm scope, but you will sacrifice low-light performance. If you want to digiscope (take photos through your scope) then choose a bigger objective, because more light will get to the camera.
What’s best for low light?
The size of the objective determines how much light enters a pair of binoculars or a scope. How much comes out the other end depends on the design, glass and coatings. A bigger exit pupil (see box) gets more light to the eye. But our pupils become less able to dilate as we age, so you might not be able to use the extra light. An 8x42 gets more light through than a comparable 8x32, but you may not see it.
What’s best for watching insects?
There are plenty of binoculars that focus to 2m or less, but to get really close try Pentax Papilios – these focus to 50cm.
What about scope design?
Scopes can be straight, with the eyepiece in line with the objective, or angled, with the eyepiece pointing upwards. Angled scopes take some getting used to. You look down into the eyepiece – this is comfortable and enables you to set your tripod lower, increasing stability. Angled scopes also make it easier to share the scope with people of different heights. A decent tripod is essential too.
TIPS FOR TESTING:
1. It’s best to try out several different binoculars before you buy, and in poor light conditions. Choose a seller with a good returns policy.
2. Make sure the image is sharp, bright and easy to focus.
3. Check that all of the colours you see look natural.
4. Colour-fringing should be minimal (look for yellow/purple fringes around pale objects or telegraph poles, wires and the edges of buildings).
5. Check the close focus – it may be better or worse than the quoted distance.
6. If you wear glasses, keep them on when testing products.
7. Make sure you are happy with how the instrument feels in your hands. Would you be willing to carry it for hours on end?
8. Check the guarantee.
9. Choose what works for you.
This compensates for any difference between your eyes. Make sure it works (ask the seller how to do it), and that it can be locked into position or is stiff enough not to move once set.
These cover the eyepieces to protect them from the elements (and crumbs from your picnic lunch).
These usually twist up and down, often with intermediate positions. Check they stay in position and don’t wobble. If you wear glasses, wind the eyecups down to ensure you can see the whole field of view.
Tethered objective covers
Not pictured, but when supplied these attach to the barrels and sit on the ends of the objectives.
This should be stiff enough to hold position. Adjust it so you see one clear circle.
Make sure you can reach this comfortably, and are happy with both how much ‘travel’ there is and how stiffly or smoothly it moves.
Ensure you are happy with how your binoculars hang against your body – some pairs don’t hang flat.