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One of the professionals, whose massive
lens and camera were mounted on a miniature version of the Eiffel
Tower, confirmed that a yield of 10% of shots was pretty good.
My camera was a standard Single Lens Reflex with a zoom lens to
210mm at f/6.2. But I am more easily pleased and, a true amateur,
“its not the winning but the taking part which matters.”
I wished for a longer zoom so that I could capture some detail
during the still moments. Then I bought a digital camera, which
has the enormous advantage that the failed shots cost nothing.
It is a Panasonic DMC-FZ3 with a 12 times zoom which is equivalent
to 32mm to 420mm on the usual SLR. This covers the full width
of the stage to portraits. It can even maintain an aperture of
f/2.8 over the whole range! I can’t find a lens for the
35mm camera, or any other, with this specification even when browsing
the Internet. I think that, maybe, one of the professionals has
a prime, non-zoom, lens of this length; he also has a trolley
for his equipment. The major disadvantage of the digital is that
the camera likes to take its time in focussing and then waits
before opening the shutter. This is obviously a further disadvantage
for action shots but rejects still cost nothing and I have been
pleasantly surprised by the quality and clarity of those shots
which are not blurred. At full zoom and 1/15 sec exposures, camera
shake is a major problem, even with optical image stabilisation
(another novelty) so I jam my lightweight tripod between the seats
with some success.
It is interesting to realise that the electronic miniaturisation
has shrunk the lens to the same extent. The image size for a 35mm
camera is about 24mm high but it is only 3.42mm on mine. The pixel
resolution is 3M, i.e. 1512 x 2016 so the chipmakers have managed
to squeeze 442 pixels per mm into the image plane. Is the lens
up to this? (Nostalgia reminds me that the most CMOS transistors
we could manage economically on a single chip were some 300 in
1970, against the current millions.)
It’s hard to get detailed information on lens resolution
that may be compared with pixels. I recall that 40 lines per mm
on an SLR was pretty good and an internet search finds that a
50 lpm is highest some contributors have found on film and 80
lpm is highest on an optical bench. I’m sure these tests
are limited to consumer products. We need two pixels to define
one line but even so, my camera is looking for 200 lpm from the
lens.
At Christmas, I used the flash with full zoom and maximum aperture
when a daughter was holding my cat. This eliminated camera shake
and subject movement entirely and I was delighted to find that
I could print up to A3 with all the clarity on the cat’s
facial hair that I could wish for. This camera has only 3.1 Mpixels
arranged as 2016 X 1512 and conventional wisdom in the photo magazines
says that this can manage a clear 6.7 x 5.0 inch print, or an
A4 print at the lower if you’re not fussy.
A friend has an Olympus C80808WZ with a 5 times zoom equivalent
to 28 to 140 mm on a 35mm camera. This has 8 Mpixels (3264 x 2448)
and the image 6.6mm high giving 370 pixels per mm; close to the
density on mine. The larger the image size, the fewer chips per
batch and a lower manufacturing yield so it’s no surprise
that his price listed on the Internet is nearly three times greater
than mine. My friend doesn’t need a long zoom and is also
delighted with the image quality compared with a 35mm SLR
There is no doubt in my mind that the lens quality is more important
than the number of pixels in a digital camera and it is great
to find that, at least in these two examples, both are satisfactory.
Unfortunately, the ordinary reviews found in High Street magazines
only give pixel data. I strongly advise potential purchasers to
check out the camera with pictures before making a purchase. Within
our club, this need be no problem. We all have computers and ink-jet
printers and many have a digital camera. There are only two sizes
of memory card so borrow them, take some pictures in the shop
and check them out. Either a brick wall or small print will do
as test cards - or has anyone anything better?
Finally, hardly any reviews mention depth of focus or depth of
field, which is very important in portraits and landscapes, for
example. The shorter the focal length of the lens, the greater
the depth of field. For example, a 35 mm camera with a 50 mm lens
set to f/5.6 can get a sharp image over the range from 24 ft.
to the horizon if it is focussed on a subject at a distance of
48 ft. If I set my camera to the same field of view and aperture,
I can get a sharp image from 3ft. 8ins to the horizon. This represents
a real advantage in landscape photography.
Neville Durrant
Security
researchers have discovered an attack aimed at would-be visitors
to Google.com, one that attempts to download malicious programs
onto the computers of people who simply mistype the search giant's
Web address.
According to security specialists, unsuspecting Web surfers may
be bombarded with various types of Trojan horse threats, spy ware
and backdoors when they go to "Googkle.com." The scheme
is meant to take advantage of sloppy or hurried typists.
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