How to ChooseChoosing your first pair of binoculars can seem like a daunting task when faced with the myriad of different shapes, sizes and prices. However by following a simple selection process, you can eliminate the majority of the unsuitable models leaving you with one decision; how much to spend.
Although we try to recommend binoculars that are suitable for particular activities, it is always a good idea to be armed with at least a basic knowledge of what to look for.
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 Numbers"What do the numbers mean?" is a common question. Binoculars are always described by two numbers, for example 10x50 or 8x42. The first number is magnification so in the case of a pair of 7x50 binoculars the image will appear to be 7 times closer. The second number is the diameter of the objective in millimetres. Generally the larger this lens is, the brighter the image will be. (Binoculars are essentially two tubes with lenses at each end. The small lens that you look into is called the eyepiece (or ocular lens) and the large lens, at the other end, is known as the objective lens)
Choosing the right binoculars needs one vital piece of information. What do you want to do with them?
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 | More about Birdwatching
Choosing for Bird-Watching
Bird-watching is enjoyed from both static locations, for example from a window at home, and as a more mobile pastime, perhaps during a country walk. Whilst you may wish to purchase one pair of binoculars that can do both, be aware that your choice must always be, by necessity, a compromise. |
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A nice big pair of binoculars will begin to feel like a millstone around your neck, when on a long country walk, whereas a more compact pair may not give you the magnification or light gathering power you want when observing at home. So the choice of a compact, lightweight pair of binoculars against a mid or full sized pair should be based upon where you expect to be using them most.
Typical good power ranges for bird-watching are 6x32, 7x42, 8x40, and 10x42 or 10x50. These sizes combine the best light gathering ratio's with the maximum useable hand held magnification. (The 10x is sometimes too much to get a nice wide field of view). If you are happy to observe from only static locations you might consider buying a tripod to support heavier, more powerful binoculars but be aware of the limitations of higher magnifications before you spend your money. Higher magnifications generally reduce your field of view making it harder to track birds on the wing. If in doubt, please call us for a more detailed discussion. |
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Do not buy zoom binoculars for bird watching as, at the higher magnifications, they do not gather enough light for the early morning or late evening observing sessions and are generally of poorer optical performance than comparable fixed focal length binoculars.
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 | More about Astronomical Binoculars
Choosing for Astronomy
Astronomical observation requires similar light gathering characteristics to that of bird-watching as ensuring that you are able to gather the maximum amount of useful light to your eye is a must. But where lower magnification is essential for handheld use field of view, for the tracking of moving objects, is of little or no importance.
Typical good, hand held power ranges for Astronomy are 7x42, 7x50, 8x40, 8x42, 9x63, 10x42, 10x50, 12x50 and 15x70. Higher magnification, for example 20x80, 20x88, 20x100 and 20x110, should only be used in conjunction with a good, heavy duty tripod, All of these sizes combine the best light gathering ratio's with the maximum useable magnification.
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Although you are unlikely to be stargazing whilst on a long country walk, the weight of your binoculars will still be important when you consider that you will often be holding binoculars above your head for extended periods of time. After several minutes, the ache building up in your muscles will cause your hands to shake and thus make clear observation more difficult.
Once again, if you are in any doubt about your choice of binoculars, please call us for a more detailed discussion. As before, do not buy zoom binoculars for astronomical use as they do not gather enough light for night time observing sessions and are generally of poorer optical performance than comparable fixed focal length binoculars.
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Choosing for Sports
Sporting events like motor racing, horse racing or even your child's school sports day are where zoom binoculars really come into their own. Viewing the wider panorama of the activity serves to immerse you in the action whilst the ability to zoom into a particular feature or event allows a more personal sense of participation.
The particulars of which zoom-ratio to light gathering ability to choose are really based upon how far from the action you expect to be. Obviously the larger the objective lens, the better the light gathering will be, but again do you expect to be able to carry the binoculars around in your pocket or are you happy to wear them around your neck all day. |  |
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For occasional use we tend to recommend the more compact sizes with the optical performance being secondary to the convenience of having them with you more often. An objective lens size of 30mm or less is fine. However, if you tend to visit sporting events on a regular basis then perhaps a larger format would suit the brightness and clarity you require. Bear in mind that zooming into the action will cause the image to become darker. This will not usually be a problem during the day but may be more troublesome if the event runs on until late evening.
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 | More about Binoculars for Outdoor Pursuits
Choosing for Outdoor Pursuits
Hiking and other outdoor pursuits tend to have a more general list of requirements and a rugged, rubber armoured pair of binoculars seem to be the order of the day. An important point to remember is if your activity is based around water or you are likely to get caught in the rain, then waterproof binoculars are essential.
Marine binoculars at a 7x50 ratio are almost the industry standard for all boating activities. Although the exceptional light gathering ability is partly wasted on those who have passed their 30th birthday, the magnification makes handheld use more practical. Especially if the platform you are standing on is anything but steady. Marine binoculars are generally nitrogen purged and waterproof, with some models even featuring a compass.
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Your choice of binoculars should suit your activity. Will you be carrying them in a back pack? Will they get in the way if worn around your neck? Are they likely to be banged about too much if kept in a pocket? Only you can know for sure. If in doubt, it is usually best to try a compact pair to begin with.
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Choosing for Travel
Travel binoculars can be summed up with one word. Compact. Do not consider anything else unless you are willing to carry a bulky pair of binoculars everywhere you go. To a restaurant, to the pub, to the beach, on public transport, to public toilets (Don't laugh. You would be surprised at how inconvenient a large pair can be.)
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Trying to keep an eye on your expensive pair of binoculars whilst sitting eating a meal is too much work for what should be a relaxing break. And don't forget, you'll probably have your camera with you as well!
Higher magnification will suit daytime use and slow moving or static subject matter, but too high a magnification (above 15x) will usually require a tripod. Higher magnification will also makes the image look dimmer and so at dawn or dusk you could experience problems with obtaining a clear and vibrant resolution of the subject matter. That said, any compact roof-prism or zoom is suitable for travel. Pocket sized is very useful but if you are happy to carry them around your neck or in a bag all day then mid sized is also feasible. (For a fuller explanation of prism types and other technical information, please read our technical section)
Lower magnification suits viewing faster moving subject matter or low light conditions. Low magnification is also better suited when it is difficult for you to hold binoculars steady, for example travelling in a car or sailing.
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GenerallyThe above simple guides conclude our recommendations for a cross section of activities. Please call us if you wish to discuss your requirements in greater detail. Value for money, with all of the improvements in modern production techniques, is guaranteed. These days, buying a good pair of binoculars at a budget price has never been easier however our advice has always been the same, buy the best optics that you can afford but always match the specification to your needs.
There is a good reason why one pair of binoculars will cost you £29.99 and another with a similar specification will cost £299.99. Build quality, components and materials used can always be factors. Another reason for the price difference between one pair of binoculars and another can be brand names. The confidence that you feel when buying a product with a name that you recognise is usually as a result of advertising and marketing. The initiatives that generate brand awareness cost a great deal of money and the products they promote carry the additional cost of this activity. |
Technical
Those who want a more detailed knowledge as to the technical specifications of binoculars, please read on. |
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Exit pupil measurement is obtained by dividing the diameter of the objective lens by the power of the binoculars. This will give the measure of how bright the image will be when looked at through the binoculars, but as we get older our pupils tend to get smaller and so binoculars with large exit pupils may not be as useful.
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If the beam of light from the binoculars is wider than the pupil of the eye, the excess will not get in and so the eye is unable to see it. In low light conditions a young person's pupil may expand up to a 7 or 8mm diameter whilst the pupil of a 30 to 40 year old may only expand to about 4 or 5mm. Thus a pair of 7x35 binoculars with an exit pupil of 5mm (35 divided by 7) would be more than adequate for an older person but inadequate for a young observer
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More Technical Information about Binoculars - Glass
Prism glass in most binoculars, are manufactured from borosilicate (BAK-7) glass or barium crown (BAK-4) glass. BAK-4 is the higher quality glass providing a brighter image and better edge to edge sharpness.
The prisms in a pair of binoculars bend the light in order to reduce the size that a straight optical path would require. It also turns the orientation of the image from upside down to the right way up.
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Porro prism binoculars are perhaps the easiest design to manufacture, and therefore has the advantage of being cheaper to produce. The objective lenses are typically spaced further apart than that of the eyepieces but this is not always the case and they are sometimes closer together in compact models. They are typically brighter than comparable roof prism models but are usually much bulkier. Porro prism binoculars also generally provide greater depth awareness.
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Roof prisms are a newer design with the advantage of being smaller and more compact than porro prisms. This allows them to be fitted into smaller housings making for more compact binoculars or spotting scopes. Alignment is often more problematic as miniscule alignment errors will cause a degradation of image. As already mentioned, they are not as bright as Porro prisms as the mirrored surfaces tend to lose some light. The exception to the rule is roof prism binoculars from the likes of Zeiss, Leica, Nikon and Swarovski. The binoculars sold by these manufacturers are likely to be too expensive for all but the most dedicated observer.
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Coatings are an essential part of almost all optical systems. Whenever light enters or leaves a glass element, between 4 - 5% per cent is reflected back. With many binoculars having as many as sixteen glass to air surfaces, less than half the light got through to the eye in early binoculars. This lost light ended up bouncing around inside the binoculars making the image very hazy and hard to see. With modern anti-reflective coatings, more light reaches your eyes and as a result the image is brighter and clearer.
Coated, or single coated binoculars have a single layer of coating on at least one lens surface. Fully coated binoculars mean that every glass to air surface has one layer of coating. Multi-coated are perhaps the most common coating system in binoculars today with some glass to air surface being coated, usually at least the front and rear lenses, with multiple layers. Finally the fully multi-coated binoculars being the best level of coating available, with every glass to air surface covered with multiple layers of high quality coatings.
Eye Relief can be a major consideration when buying your first pair of binoculars, for instance people who wear glasses should aim to buy binoculars that offer better "eye relief" as having to take your glasses off to use them can be frustrating. Eye relief is the measurement of how far back from the eyepiece your eye can be whilst still seeing the whole field of view. Any further back and you will see only the centre part of the image. Eye relief for binoculars tend to be from about 10 to 17mm. Binoculars with fold down or screw style eyecups let spectacle wearers get closer but you will still need binoculars with a long eye relief of 14mm or more.
Eyecups allow the user to just comfortably touch their face whilst helping to block out lateral light. They are typically rubber eyecups that can be folded down, or the type that either twists or slides up and down on the eyepiece. Spectacle wearers always have the binocular eyecup rolled down, thus allowing the widest possible field of view.
Field Of View is the horizontal measurement of the circular area visible at 1000 yards (or sometimes metres) High power binoculars have a narrower FOV and, as already mentioned above, makes following fast moving subjects difficult.
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