Olympus IS-2DLX, Инструкция по эксплуатации

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FLASH
Flash Strength
The flash on the IS-2 employs a new exposure
control system that combines the advantages of
both "flashmatic," used in compact cameras, and
"auto flash", found in SLR cameras. Flashmatic
emits a full-strength flash while automatically
adjusting the aperture for proper exposure. This
system is effective in most cases. However, subjects
at extremely close range tend to be overexposed,
and the background too dark, because the
narrowest aperture setting has been selected. Auto
flash varies the amount of light emitted by the flash,
and sets the exposure by measuring reflected light.
Depending on the background however, the wrong
exposure for the main subject can be selected. For
example, with a white background, the subject may
appear too dark due to the level of reflected light
received through the lens. The reverse is true for a
dark background.
The IS-2 adjusts both the aperture and flash
strength to give you perfect exposure every time,
taking into account the effect of the background
light and the distance to the subject.
Dual-Strobe Intelligent Flash
The flash of the IS-2 is distinguished by two
emission tubes. One of the most important functions
of a flash is to distribute light evenly throughout the
frame. When a zoom lens is used, the area that can
be lit by a single flash is determined by the wide-
angle focal length. When telephoto is used, the light
is wasted because the light is spread over a wide
area. If this wasted light is concentrated on the
picture area however, the working distance of the
flash will be increased. Solving this problem is
crucial to effective telephoto-flash photography.
The zoom flash system found in some cameras is
one solution to this problem. With this system, the
distance between the xenon tube — which is the
emission source of the flash — and the reflective
material behind it is varied according to the focal
length of the lens. When telephoto is used, the light
from the flash is condensed more intensely. (The
distance between the xenon tube and the
condenser lens can be varied for the same result.)
So why does the IS-2 incorporate the dual-strobe
system? Because the dual-strobe system can utilize
the light more effectively while achieving more
uniform lighting than the zoom flash system is
capable of. The zoom flash system also cannot alter
the actual shapes of the reflector and the condenser
lens. In practice, these two factors greatly affect the
even distribution and condensing intensity of light
from the flash. The zoom flash sacrifices the
effective use of the light's intensity for even
distribution. To achieve both optimal condensing
intensity and even distribution, Olympus developed
the dual-strobe flash system with two sets of tubes
and a reflective backing that are ideal for both wide-
angle and telephoto photography. This makes a
powerful, versatile flash with GN 20 (ISO 100 • m) /
GN 66(ISO 100 • ft) possible.
The lower tube is designed for telephoto
photography and offers GN 20 (ISO 100 • m) / GN 66
(ISO 100 • ft). The upper tube is an intelligent
variable-power flash offering GN 15~1.6 (IS0 100 • m) /
GN 50~5.3 (IS0 100 • ft). When the flash strength
should be less than GN 15 (ISO 100 •m)/GN50
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