You first set either the aperture or the
shutter speed – the choice is yours.
Let’s say you first select the aperture.
Now rotate the dial that controls the
shutter speed, till the cursor comes to
0 (zero). When that is done, you have
“nulled” the exposure.You could select the shutter speed first
if that’s what you want. In that case,
you need to rotate the dial that controls
the aperture, till the cursor comes to
0 (zero). Again when you do that, you
would have “nulled” the exposure.When should you use Manual
exposure? Does it offer any
advantage over the other exposure
modes?
Under certain situations – which I’ll
explain shortly – Manual exposure
definitely has an advantage. At other
times, you will likely notice that the
exposure recommended by Aperture
priority (A or Av) or Shutter priority
(S or Tv) is identical to that offered by
the Manual exposure mode. Manual
exposure metering takes a longer time
(comparatively), and there could be
occasions when you can miss a shot
when twiddling with the meter. Let’s
consider the following situations.
Consider that the subject is front-lit and
you are using either Evaluative/Matrixmetering or Centre-weighted metering.a) When your subject is mid-tone and
is more or less filling the frame, A/
Av or S/Tv can be used without any
hesitation.b) You main subject is very small in
size, and is not a mid-tone, but the
backdrop is mid-tone, then too A/Av or
S/Tv can be used successfully.When using A/Av or S/Tv, the
problem comes when the tonality
of the backdrop changes. As long as
the backdrop is mid-tone, you can be
certain that your camera will offer a
good exposure. Let’s take this further.Example 1: Your subject, say an
elephant, is front-lit and is standing in
front of a mid-tone background (green
trees, meadow etc). The elephant is
occupying, say, 25% of the screen
area. You are using, let’s say Aperture
priority and you find that the exposure
offered by the camera is correct.Example 2: Now the same elephant
moves and comes in front of a lighter
background (say, a toneless white sky).
If you were using Aperture priority,
your exposure will go for a toss; the
elephant would be underexposed dueto the large expanse of the lighter
background!Note: In such a situation, you could
use plus (+) exposure compensation.
But unless you are quick, you could
miss out on some crucial shots when
you are busy adjusting the exposure
compensation.Example 3: Once again the elephant
moves and comes in front of a dark
background (deep, shady trees for
example). If you were using Aperture
priority, your exposure would be wrong
again; this time the elephant would
be overexposed since the exposure
meter will be reading more of the dark
background.Note: In such a situation, you could
use minus (-) exposure compensation.
But unless you are quick, you could
miss out on some crucial shots when
you are busy adjusting the exposure
compensation.This is the time when Manual exposure
mode would have provided a consistent
exposure for the elephant in all the
three examples mentioned above.
With Manual exposure mode, there
would have been no chance for the
exposure to vary due to the brightness
or darkness of the background
because the aperture as well
as the shutter speed would be
locked. The only reason the
exposure could go wrong is if
the lighting changes, but as long
as the light does not change, the
manual mode exsposure would
give the most consistant results
in our above three examples.Another example of when
Manual exposures would
provide consistent results is
if you were photographing
someone (or something)
in front of a large expanse
of water. Depending on the
camera angle and the amount
of reflection off the water,
exposures with Aperture
priority or Shutter priority or
even Program mode could keep
varying. With Manual exposure,
the brightness on the subject
would be consistent.a ����������������������������������������������� b Mid-tone backgroundLEARNING
100 http://www.smartphotography.in
Smart PhotographyJuly 2017