Olympus E-3 Manuel de l'utilisateur - Page 7

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Olympus E-3 Manuel de l'utilisateur

Differences between photography

on dry land and under water

Light

Because part of the light beams are reflected
when they hit the water's surface, less light is
available underwater than on dry land. The lower
the angle at which they hit – such as during early
morning or late afternoon – and the rougher the
water surface, the more the light beams will be
reflected. Best results are therefore achieved
during calm seas and around noontime when
the sun is at its highest. Also, don't forget that
due to the density of water, the deeper you go,
the darker it gets – right up to the point of
complete darkness.

Colours

The further light travels down in the water, the
more colours of the spectrum get lost. This starts
with colours that have long wavelengths (red at
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The altered conditions
underwater make distances
appear shorter by a fourth.
This means something that
seems like it is 3m away is
actually 4m away. Remember
to take this into account
when using the flash under-
water and judging the
distance to the subject.
a depth of around 3 – 5m)
and proceeds to colours with
short wavelengths (blue at
a depth of around 20m).
The loss of colours not only
happens vertically, but also
horizontally. So if you are
taking a photo of a red
subject from a distance of
over 5m – even if you are
close to the surface – the red
colour will be completely washed out. Bear in
mind that if using the flash, the light must travel
to the subject and back, thereby effectively
halving the maximum distance.

Particles

Water is more or less full of floating particles.
The amount of these depends on various factors
including how clean the body of water is, the
time of year and the current or turbulences at
a given time. The particles are generally larger
than those present in the air and are therefore
more likely to have an effect on the outcome of
shots. Most common effects are reduced contrast
and clarity (dots showing
up in the photo) as well as
a decrease in the available
light, as the floating particles
also diffract light beams.
General tips:
• If possible, go diving in
clear weather
• Bear in mind the filtering
effect on colours as
distance increases
• Make use of your camera's
exposure bracketing
function (if available)
• It is often indispensable
to use a flash
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