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This image, photographed at moon-rise in
Wellington, New Zealand, required the use of a gyro-stabilizer to obtain the proper exposure in this dawn setting. The sunset in Tahiti on the far right was
bracketed to create silhouettes of the trees and huts.
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EXPOSURE AND THE GYRO-STABILIZER
By Harvey Lloyd's from the book: Aerial Photography
ISBN # 0.8174.3293.0
When there is sufficient light, shoot at high shutter speeds: 1/500 sec. to 1/2000 sec. or faster, if your camera allows.
The shutter speed you select depends on the focal length of the lens and the relative motion of the aircraft and subject below you. In a chopper, you must guard against vibration
and turbulence; in a light plane you must deal with air speed and the gravitational forces that accompany you as the plane circles around the subject.
On the ground, the rule-of-thumb for minimum shutter
speeds is approximately one divided by the focal length of the lens. That is, a 105mm lens should be handheld at no slower than 1/125 sec., a 300mm lens at 1/500 sec., a
50mm lens at 1/60 sec., a 24mm lens at 1/30 sec., and so on. In the air, I try to triple or quadruple these speeds, except when using the gyro-stabilizer. With this device,
when I'm working in low light-such as the glow of dawn or the afterglow of sunset -I can shoot from a chopper at very slow shutter speeds because the gyroscope keeps the
camera stable at all speeds. The gyro-stabilizer is an egg-shaped object about three inches in length and weighs about two pounds. It attaches to the camera body's tripod
mount and is connected by a cable to a rechargeable battery pack. The stabilizer steadies the camera against pitch (up-and-down motions) and yaw (side-to-side)
motions. Inside the egg, the two gyroscopes are set at right angles to each other. They rotate at 20,000 rpm and take about six minutes to get up to speed. You must
always position the nose of the gyro-stabilizer in the direction you are shooting. (1 once met a Fortune magazine photographer who had it sideways. It didn't work.) During one year, I used it to photograph the
dawn over El Morro castle in Puerto Rico; the twinkling lights around the harbor of Charlotte Amalie on St. Thomas; a full moon in a glowing pink sky near Wellington, New Zealand; and a dawn at Auckland; among
other "impossible" scenes.
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 When shooting directly into bright, sunlit water; you must close down your apertures to prevent the scene from becoming overexposed. In the Image
above, a graphic effect was achieved by stopping down enough to make the ship and sails a silhouette. On the opposite page, bright sunlight was used to create a reverse effect,
darkening the water and exposing for detail in the ship.
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Once the gyro-stabilizer is attached to my camera, and the light is bright, I can cover much of what is
needed for shooting with a 25-50mm or 35-105mm zoom lens. The zooms allow quick shift of focal lengths-a
great help in the air, where air time is always short. As I mentioned before, we're not always in control of
shutter speeds. When shooting over the open sea, in bright sunlight, with a polarizer on an f/3.5 or f/4 lens,
with my favorite slow film, the best shutter speed I can get is often 1/250 sec. I must slow down to 1/125
sec. to bracket fully. Only the use of the gyro-stabilizer makes this possible for sharp images. Using fast single-focal-length lenses, such as 50mm f/1.2, 35mm f/1.4, or a 24mm f/2, you can obtain acceptable
sharpness at shutter speeds of 1/30 sec., or perhaps even 1/15 sec.1 try to stay in the range of 1/30 sec.
or faster. The longer the focal length of the lens, the smaller the area of the scene it takes in-and the
slightest shake will be proportionately multiplied. In the air, the rule is: The longer the focal length, the higher the shutter speed required. As a general rule, I always use the gyro-stabilizer in the air.
Exposure Considerations
. When photographing in low light, at dawn or dusk, the use of a gyro-stabilizer is important. Fast films will also help, but you must remember that you will sacrifice image quality because of
high grain. With the gyro you can shoot using ISO 100 film at approximately 1/30 sec. and, in still air, down
to 1/15 or 1/8 sec. with wide angles. Over water, it is advisable to use a polarizing filter to bring out color
and reduce flare from the surface reflections. The best exposure is gained when the sun is high over the
water. Early and late in the day; the water will go dark because of the slanting rays of the sun. Filters
rarely eliminate haze or smog to an appreciable degree. You need to start with the best air conditions possible. If you don't have them, wait for them.
Weather Conditions. Weather is a principle concern on any assignment. You have a schedule to meet, but
the day you go up may be miserable-which is why it is a necessary point of budgeting in extra weather days
for all assignments. And what may appear or start out as acceptable weather on the ground, can turn just the opposite once you are airborne. Haze and visibility can change dramatically.
You must carefully learn to assess weather conditions: Use a good weather service, and check forecasts
daily; An excellent service is Universal Weather and Aviation, based in Houston, Texas (113-944-1622). They supply satellite forecasts worldwide, and I have found them to be as accurate as any weather
forecast can be.
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