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| Cley Spy's latest advert in the birding magazines |
In August 2001 Cley Spy
opened in the front half of an old carrot washing barn in Glandford
near the
North Norfolk coast, stocked with a handful of binoculars
and telescopes. Since then we have expanded to become the biggest
independent specialist optics shop in the country, with over 180
different models of binocular, over 40 telescopes and our second hand
stock all on shelf to be tried and tested. Over the years Cley Spy
has become the place to visit for the best advice and choice of
specialist nature watching equipment.Whatever your budget we will always give you our honest and frank advice and explain the acronyms and technical terms that you are likely to come across.
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| The impressive view from the back of our Glandford shop over fields managed for conservation. |
We regularly get visitors
travelling from all over the country because the range of stock,
viewing facilities and expertise we can offer are the best around.
Even if you can't make
to us in person we are always available to offer advice over the
phone or via the website.
Here are some of the
terms often associated with binoculars and telescopes with a brief
explanation of what they mean.
APO.
Abbreviation of apochromatic. A
completely apochromatic lens system corrects all chromatic aberration
(colour fringing). Leica's
APO-Televid scopes also have fluorite lens elements.
BK-7 and BAK-4
prisms. These are two grades of
glass, boroscilicate BK-7 (generally in cheaper optics) and barium
crown BAK-4 (delivering better sharpness)
Digiscoping. This
is the general term for taking digital photographs through a scope.
This can be done with almost any kind of camera including
smartphones, but some work much better than others. For more
information on digiscoping click here to read our blog on the
subject.
ED, HD, HR. Terms
used to denote higher-quality glass models, HD standing for High
Definition, ED usually standing for Extra-low Dispersion, and HR
standing for High Resolution. These terms are not standardised, one
companies standard glass can sometimes be as good as another's HD.
With Leica and Swarovski HD denotes models with fluorite lenses.
Eye relief. This
is the distance that your eye should be from the eyepiece lens to get
the optimum image. Spectacles wearers often need a longer eye relief
when using binoculars with there glasses on.
Nitrogen filled.
Waterproof binoculars and
scopes are often filled with a dry, inert gas (most commonly nitrogen
or argon) to prevent internal fogging.
Phase correction.
Coatings applied to prisms to
reduce dispersion, giving sharper images with better contrast and
reduced chromatic aberration (colour fringing).
Roof prism and Porro
prism.
These
are the two widely available types of binocular. It is simply the
type and layout of the prisms in the barrels (see picture). This has
some minor impacts on the image, but the big difference is the
smaller overall size of a roof prism compared to a porro prism of the
same specification.
Spotting scope,
fieldscope and telescope. These
terms are often used interchangeably or just shortened to 'scope'
when referring to birdwatching telescopes.
Birdwatching
telescopes vs. Astronomical telescopes. Birdwatching
scopes are almost without exception of the refracting type (using
lenses and prisms) whereas astronomical scopes can be both refracting
or reflecting (using a combination of mirrors and lenses). As a rule
birdwatching scopes can be used for basic astronomy, but astro scopes
do not work well for birdwatching due to not being waterproof and
producing an inverted image. Astro scopes are also relatively big and
heavy.
