Choosing a telescope
Straight or angled, fixed focus or zoom?
I've never seen
a sales graph of telescopes, but over the last 20-30 years it must
have brought great pleasure to the manufacturers and retailers of
this essential birdwatching tool. The first telescopes were made
for deer stalking, of brass with three or four draw tubes and a
leather case. Stalkers would lie back on the heather and prop the
end on their knees. The few birdwatchers who possessed one either
had to find a friendly shoulder or a convenient wall.
40 years ago, two small telescopes appeared, one a short draw-tube,
the other of fixed length. I had the latter, the Nickel- Supra,
and at last one could stand and look through a tripod-mounted 'scope,
or fix it to a car-window mount. By the 1970s, several manufacturers
were producing good birdwatching telescopes and the
revolution had begun.
first, all telescopes had eyepiece and objective lens in-line. Then
came the bright idea of putting the eyepiece at an angle. Now the
tripod could be set much lower and so less likely to vibrate. More
importantly, it meant that people of different heights could look
through the 'scope without having to adjust the tripod. (right
- straight and angled versions of a Swarovski telescope)
also started producing telescopes with interchangeable eyepieces,
giving a choice of fixed focus or zoom and, later, wide-angle. Zooming
telescopes were around from the early 1970s, but the zooming mechanism
was internal. Now, one could choose which to have or even have one
of each kind.
when there's a choice, so you get adherents to each one. Birdwatchers
started to take sides, to express firm views, even to speak disparagingly
about the choice of their friends if was different from theirs!
And this is where we are today. When you go to buy your first telescope,
or to replace your present one, do you choose straight or angled,
fixed focus or zoom?
Of course, I
cannot possibly offer an unbiased view. For the record, I have a
straight-through telescope with a zoom eyepiece. If my 'scope is
on a tripod then people have to accept that I'm taller than most
of them and sometimes a bit reluctant to lower it! However, the
reason I have a straight-through scope is not about selfishness,
but because I often use my telescope in a car. I have yet to find
anyone who can use an angled 'scope satisfactorily in a car, unless
a vehicle with unusual extra headroom. As for my zoom eyepiece,
I like to scan on low power and then zoom in on something interesting,
whether a bird or a goose ring or collar I want to read. I have
tried a fixed focus wide-angle eyepiece and was duly impressed with
the bright image, but I still prefer the flexibility of the zoom
and, at least at the top end of the market, the loss of light when
zooming is not too great.
So one ends
with the only possible advice. Try out the different types before
Ogilvie is a natural history writer and editor, formerly a research
scientist with the Wildfowl and Wetlands Trust, and resident
on the island of Islay since 1986. Until 1997, a member of the
'British Birds' editorial board and also one of the editorial
team which produced 'Birds of the Western Palearctic'.