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Photography
Architectural
Perspective Lenses
By Carter B. Horsley
Taking a snap of the farmhouse in
Christina's World is not too difficult with most of the normal
lenses that come with most cameras, but just try to get a shot
of, say, the Time-Life Building on Sixth Avenue and see what
happens.
Odds are you might be bright enough
to cross the street to try to improve your perspective and might
even borrow a friend's wide-angle lens since it is 48-stories
tall and wedged into between similar huge boxes.
If you are lucky, your friend's wide-angle
might even be a superwide, perhaps a 21-, a 20-, or a 17-mm lens,
the smaller the number of millimeters on a 35-mm camera lens
the wider its field of view.
You are likely to be rather disappointed,
however, with your results despite your efforts, unless
you friend happened to have a "perspective control"
lens designed for shooting architecture. Such a lens has
the ability to shift the plane of the lens in relation to the
film plane to enable the photographer to try to compensate for
converging lines. If you look up at a very tall building
from its base, it will seem to get narrower at the top and quite
distorted. Distortion is not widely considered to be a
virture in architectural photography, although artistic types
have always dabbled with it.
Several leading 35mm camera manufacturers,
such as Nikon, Canon, Pentax and Olympus have long had "perspective
control" lenses, but they have tended to be quite expensive
and often unsatisfactory, especially in urban settings because
of the proximity of other buildings and the difficulties of getting
an excellent vantage point from which to shoot a tall building
with little distortion.
In recent years, two of the manufacturers
have come out with 24mm "perspective control" lens,
Olympus and Canon, whereas the other manufacturers offer only
35- and 28-mm "perspective control" lenses that have
a much narrower, though still wide, field of view.
The former is a most impressive piece
of glass, putting many hemispherical fish-eye lens to shame.
Its lens mounting permitted it to be shifted several degrees
in the horizontal and vertical directions.
The latter was much more sedate in
size, but still very formidable looking, not terribly unlike
a Rube Goldberg stovepipe hat, with bulges and projections. The
Canon not only could shift its mount, but also tilt it several
degrees, a feature common to expensive large-format cameras,
those behemoths with bellows and drapes and tripods and large
film-holders.
Both the Olympus and Canon have recent
street-prices of about $1,100-$1,500 and for that money you do
not get automatic focus because of the complexity of the lenses,
and the lenses, which both have relatively slow maximum apertures
of F/3.5, by themselves will certainly not automatically guarantee
that you will get great architectural photographs.
The lenses help, of course, but you still need good lighting,
great vantage points and artistic skill in composition.
In many cases in New York, even 24mm
is not wide enough and a 17-mm shot may be better to get everything
in the shot but it will have serious distortion depending on
the vantage point.
The shift feature of the Canon lens permits a variety of other
interesting special effects such as eliminating reflections,
excluding unwanted objects from in front of the main subject,
focusing the entire subject plane which is not parallel to the
film plane, focusing on just a specific part of an object, creating
panoramic joined pictures, correcting image distortion caused
by shooting from an inclined position.
Canon also makes tilt/shift 45 and
90-mm lens that are not meant for architecture. Both the
Canon and the Olympus 24-mm lenses are beautifully made, but
slight knudges can sometimes move the lenses.
Alternatively, one can forget the
convenience and speed of the 35mm format and move up to a large
field camera that has adjustable horizontal and vertical movements
for its bellows, but that is much more cumbersome and much more
expensive. These cameras permit much wider/longer swings
and shifts, but they are impractical for all but the professional
architecture photographer shooting on a big budget.
Another alternative is to shoot
with a very-wide angle 35mm lens such as a 17m and then crop
the image. This can produce reasonably satisfactory results sometimes
if it is aimed properly, but the cropping, of course, reduces
the resolution of the final image
because it is a smaller portion of the already small negative.
Even with the best lenses, one should
remember to bracket exposures as it is very difficult to find
the right exposure for the building, its shadows and highlights
and reflections as well as the sky. Also, one wants to shoot
usually in early morning on bright, clear days to accentuate
shadows that add depth to the image.
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