Buying Binoculars Tips
There are several details you will want to consider when buying your first pair of
binoculars and deciding "what are the best binoculars for me?" It's important to take
into consideration your specific activity when making your choice. You may not have
the same requirements for backyard birdwatching as you have for onboard marine use.
Here are several activities that will benefit with the use of binoculars. Birding
and simple backyard birdwatching, hunting, fishing, boating, security & surveillance,
sport and entertainment viewing, casual travel and star gazing. All of these
activities are greatly enhanced with the use of a good pair of binoculars.
What do the numbers 8X40 mean ?
The 8 means that the viewed object will be 8 times closer than it appears to the
naked eye. So bigger is more powerful but not always the best choice. The more
powerful the lens is the more susceptible to blurring it is due to hand tremor or
other movement. So it's wise to stay below 8X for casual off the cuff viewing. You
will need a tripod or some sort of support to use the more powerful binoculars for
astronomy.
The 40 represents the width of the exterior lens. The bigger the lens the brighter
and sharper the image will be. However the lens will also be heavier making the
binoculars more awkward and clumsy to handle.
Field of view
Field of view is how much of the scene you are looking at will show up in the
binocular view. Two factors determine the field of view, magnification and the
design of the eyepiece. The higher the first number (8X40 or 10X40) the more detail
you get but less width of the over all scene. A wide angle design eyepiece resolves
some of this issue but is a bit spendy, some brands offer a less expensive wide angle
eyepiece but the clarity generally suffers.
Prism types
Binoculars have prisms in them so that the image will appear right side up. The
optical glass used to make prisms are called Bak4 used in the high end binoculars and
Bk7 which is used in the lower priced, cheap binoculars. There are two basic styles of
prism, porro and roof.
Roof Prism
The sleek roof prism arrangement makes for a more slim and easy to handle pair of
binoculars. The quality roof prism systems will be phase corrected and include silver
coated mirrors. They will usually have an interior focusing mechanism which further
adds to the sleek easy to handle quality's of this type of binocular. It will also
raise the price considerably.
Porro Prism
Most old school binoculars have the porro prism system which has the outer lens and
the eyepiece offset. This makes for a bulkier and heavier pair of binoculars. Even
though the porro system is bulky it is very efficient and does not lose light to
mirrors as it does not use them. You can get a good pair of inexpensive binoculars if
they use the porro prism setup.
Lens Coatings
Binocular lenses have chemical coatings on them to prevent the loss of light that
passes through them and this helps to create a brighter image.
There are basically three lens coating specifications.
Fully Coated: The lens will have a single coating that will help reduce light loss.
Multi Coated: The lenses but possibly not all, will have several layers of chemical
coating that will enhance even more of the binoculars ability to not lose light.
Fully Multi Coated: All lenses will have the multi coatings on them, giving them the
maximum light retention that is possible. All of the high quality binoculars will
have Fully Multi Coated lenses.
Taking the above basics into consideration will help you decide on what will be best
for you when choosing your binoculars. You should also consider how weather proof
they need to be (marine binoculars), armoring ? (hunting binoculars) lightweight but
powerful (birding binoculars). Are they easy to focus ? Can you look through them
easily while wearing eye glasses ? Are they mountable ? And lastly how heavy and
awkward are they? Once the binoculars get past 30-35 oz you should consider a pair of
binocular harnesses to ease the stress and strain on your neck. Good luck finding the
best binoculars for you.