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 The
delightful arc of a rainbow’s bright ribbon is merely
the outer edge of a cone of redirected and concentrated
light centered on the antisolar point; here projected on
the land and sky near Bega, New South Wales, Australia.
A late afternoon summer storm in January 1989 crafted
the scenic skyscape, and was preserved on Fuji RDP ISO
100 film with an Art Panorama 6x17 cm format camera. Ern
Mainka
If there’s ever a case
for carrying both your umbrella and your camera with
you, it’s rainbows. Relatively rare, largely
unpredictable, and always silent and fleeting, it helps
to be observant and equipped when rainbows glisten.
Equipment.
SLR 35 mm camera or digital camera; tripod, polarizing
filter, 100 ISO film; raingear for yourself and your
equipment.
Because the solar elevation determines the rainbow’s
size, it is just a sliver on the horizon when the Sun is
high, but when the Sun is on the horizon, the primary
bow is 84° wide and the secondary bow a gaping 104°. If
you want to capture such full spans, you’ll need a 20 mm
wide-angle lens, but a 28 mm can do well with partials
and smaller bows. A telephoto lens can be used to
isolate supernumerary bows and individual colors bands
to make them appear wider relative to their
surroundings.
 Composure.
Sometimes serendipity comes in anticipating it, so you
may want to be set up overlooking a scenic landscape
before the rain ends. That way, when the rainbow makes
its brief appearance (remember to be looking in the
opposite direction from the Sun), you are a ready and
interactive spectator. An interesting foreground adds
further interest and a sense of proportion and place.
Technique.
Rotate the polarizing filter until the rainbow reveals
its brightest coloration. Compensate for the loss of
light because of the filter (up to 1.5 stops), but
underexpose by a half to a full stop to better saturate
the colors. To improve your chances of perfection (and
some more serendipity) bracket your exposures. © Tim Herd
The rainbow doesn't
end at the horizon; indeed, if you are high enough above
the horizon, you may be able to see the complete circle
of the rainbow's spectral border. The bright, broad
bands of the familiar display are color separated by
falling raindrops—here
emblazoning the remnant of a storm near Socorro, New
Mexico on August 24, 2005. Harald Edens
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