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The key to choosing binoculars and telescopes comes down to the ability
to test in 'field' conditions, comparing like for like products in an
unhurried manner. If you cannot see further than a few hundred yards/metres,
and/or find yourself looking at the inside of a shopping centre or high
street it's unlikely you'll have made the correct choice.
All in focus shops and field events have the viewing facilities that will
allow you to make the right decision, guided by our highly knowledgeable
staff that work commission free and have many years experience in both
optics and birding.
Telescopes for birdwatching
have become very popular. Once you've used one, you'll see why. They add
an exciting new dimension to birdwatching. Unlike binoculars, scopes can
be purchased in sections - body, eyepiece, photoadaptor and usually with
a suitable support such as a tripod. You need to take trouble over getting
the combination of parts right.
What
magnification do I need?
Magnifications
are available from as low as 15x or as high as 50x, or even higher with
some specialist scopes. Some have a fixed eyepiece, usually with magnification
of 20x and a relatively wide field-of-view, but many have a range of interchangeable
eyepieces to choose from. 20x to 30x wide angle are good for general use,
and a 40x may be useful for distance work, e.g. viewing raptors.
At high magnifications you lose image brightness and field-of-view, you'll
need a fixed support, and it's harder to focus precisely. Eyepieces of
60x and above can only be used in bright light and on a fixed support
(for viewing stationary birds). Bigger doesn't mean better! Variable focus
or 'zoom' eyepieces work well with some scopes and usually cover ranges
of 15-45x or 20-60x.
The most compact scopes have 60mm objective lenses, which are ideal for
general viewing, less so if the light is poor. Using a 20x or 22x wide-angle
eyepiece ensures that you get maximum light-gathering. There are plenty
of versions with larger objective lenses, usually between 75mm and 80mm
diameter. These have increased low-light capability, but also increased
size and weight. They are at their best with a 'zoom' eyepiece, and with
high-powered eyepieces of 40x or more you get better image brightness
too. Wide-angle 20x or 30x eyepieces also do well on these models.
Basic
guidelines
For
field work, walking and general observation, try a compact 60mm scope
with a 20x or 22x wide-angle eyepiece. For greater power choose a 30x
wide-angle or 40x. In low light, or when observing from a hide or any
other fixed position, the larger 75/80mm scopes are ideal. You can fit
fixed 20x, 25x or 30x eyepieces, or a 20-60x 'zoom' eyepiece.
'Zoom' eyepieces are fine when you need a range of magnifications, but
the field-of-view is less than fixed eyepieces at equivalent magnifications.
If you wear glasses, you can get eyepieces with a fold-back rubber cup:
you can keep your glasses on, but remember that you may lose some field-of-view.
Straight
or angled eyepiece?
Straight
Easier to use and
find birds at first.
Easier to use with a shoulder-pod.
Best for hide use or viewing from a vehicle.
Angled
Easier to watch birds in trees, or viewing downwards, e.g. seabirds from
cliffs
Useful if sketching or using a notebook.
Your tripod doesn't need to be so high, so it's more stable.
More comfortable for long term observation.
The angle of the eyepiece doesn't affect the interchangeability of items
such as photoadaptors. The choice depends entirely on your personal preference.
Fluorite
and ED (Extra Low Dispersion) Optics
Some
products are available with ED, HDF or Fluorite glass optics. These are
high-grade optical glass elements (used in objective lens construction)
offering enhanced image definition, higher contrast and more accurate
colour. You can find them across the price range, but they are most effective
in top-quality scopes specially designed to get the best out of Fluorite
and ED optics.
How
to care for your equipment
Don't
forget to insure your equipment on an 'all risks' basis.
Do NOT let your optical instruments get wet unless you're sure they're
guaranteed waterproof.
Don't let them suffer impacts or extremes of temperature.
Don't over-clean the lenses this can damage them, and often does. Just
breathe lightly on the lens surface and wipe carefully with a micro-fibre
cloth. Don't use lens cleaning fluids or impregnated cloths, which leave
residues and cause smearing.
If your binoculars or telescope do get wet and moisture reaches the interior,
let them dry out in a warm atmosphere and then take them to a specialist
dealer for cleaning and servicing. On no account try to do repairs yourself.
Letting air into an already moist instrument just makes matters worse.
If you're using your scope in the field, do NOT hang the tripod under
the scope by using the scope's stay-on case strap to carry the whole kit.
This can prove to be an expensive mistake! Place a tripod strap round
the tripod so that the scope sits on top of the outfit.
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