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How
to choose binoculars most suitable for your needs, continued
Pricing Justification
When considering how to choose binoculars price is a major consideration.
There are several factors that will affect
the price.
The first is the type of lens and coating
that is used; glass lenses, which are coated on each side with multiple
layers, will produce a picture at high magnification which is substantially
clearer and brighter than that produced by plastic lenses.
Plastic lenses, on the other hand, tend
to make the binoculars lighter, but will be substantially more expensive
for the same grade of picture quality.
If the binoculars are to be used in clear
conditions, at a low power, then this may be acceptable.
If more variation in lighting (i.e. dusk
and night use) is expected, then one should opt for better quality
optics, and hence a higher price tag.
The build quality will also affect the price.
More rugged, shock-proof binoculars destined
for use in harsher conditions (marine or backpacking) will cost
more than those which do not need to be waterproof or shockproof.
Uses and Solutions
Before you decide how to choose binoculars you need to consider
the solutions for differing environments.
Single scopes or spotting scopes, for example,
are often used for hunting.
Here, since they are, in effect, half the size
of a regular pair of field glasses, better quality optics can be
afforded, as the cost will be proportionally lower.
Hunting glasses need to be good in all light
conditions, from dawn to dusk, and even have limited night vision.
In general they should be lightweight, but probably
with a smaller magnification, and larger objective.
High power spotting scopes, or binoculars, where
the power exceeds 10x will need to be mounted on a tripod.
The best models will be ones with a very large
objective lens, suitable for use in many conditions, but will be
too heavy and cumbersome for use on the move.
Finally, if you are going to do hiking while hunting,
it is important to note that optics are very fragile, and so plastic
lenses over glass ones, and a rugged case are probably going to
be more important than high power, or the ability to use them at
night.
As a curio, it is possible to buy, from Zeiss,
a pair of binoculars which have a mechanical anti-jog mechanism
which allows for extremely high magnification, but without the shake
associated with it.
They come in at around $4000.
Digital binoculars are a cheap alternative, and
can be picked up for considerably less ($200), and usually have
a built-in camera.
They are not perfect optically, with a resolution
of around 3 mega pixels, but will suffice for the hobbyist.
Jargon Explained
There are many different terms that are bandied about when reading
descriptions of binoculars and before rushing off to the store,
it is worth understanding some of the more esoteric ones.
For example, there are several different descriptions
of the coating that has been used (see Power, Light and Weight)
to reduce the amount of light reflected back through the lenses
during magnification:
- C : Some surfaces coated
- FC : All surfaces coated, except plastic
lenses
- MC : Some surfaces have been coated in
multiple layers
- FMC : All glass surfaces are coated
with multiple layers.
In the last case, one would expect a good quality
piece of optics to be able to transmit between 92% and 95% of all
available light back to the eye.
The “Exit Pupil” is also important and can be
calculated by dividing the power by the objective size and yields
a value which is very important – it is the diameter of the light
fed to the eye.
Given that the average human pupil ranges in size
from 2mm to 7mm depending on the available quantity of light, it
is clear that, in the midday sun, an Exit Pupil value of 4mm (for
example) will mean that 50% of the image returned to the eye is
lost.
By a similar token, if the value is smaller than
7mm for a night scope, then it is not taking advantage of the human
anatomy.
A word of advice – always use night scopes in
the dark, to keep the pupil as wide as possible; this means no,
or very low, light around the place that you choose to hide out
whilst communing with nature.
Finally, if the phrase ‘Eye Relief’ is mentioned,
then it refers to the way that the eyepiece is set up with respect
to the other optics in the device.
Most glasses will come with eye relief between
9mm and 13mm, and is the distance from your eye to the lens before
your field of view becomes limited.
If you wear eyeglasses, then eye relief above
14mm becomes desirable, since you will already have a certain amount
of distance between your eye and your eyeglass lens, which you can
not change.
Given this, if your chosen optical device has
a small eye relief, then you will have a very restricted field of
view, and miss out on most of the picture!
As you can see when you need to decide how to
choose binoculars most suitable for you there are many aspects to
consider.
Hopefully this article will have made your job
easier.
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About the Author: Guy
Lecky Thompson is a successful freelance writer offering guidance
and suggestions for consumers regarding binoculars
His many articles give information and tips to help people save
money and make smarter decisions.
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