very EOS camera
apart from the
400D, 2000D and
1300D feature four
metering modes: Evaluative,
Centre-weighted average,
Partial and Spot. The most
sophisticated of these is
Evaluative. It divides the
viewfinder into a number of
zones – from 63 zones in the
EOS 400D to 384 zones in the
EOS R5 – then compares the
readings from each zone before
calculating the exposure.
The subject of the shot
doesn’t need to be bang in the
centre of the frame when you
use Evaluative. This is because
the camera uses the AF points
to determine where the subject
is – it presumes that it’s under
the AF point that’s achieved
focus – and it priorities the
exposure accordingly.
As good as it is, there are
times when Evaluative needs a
helping hand, in the form of
exposure compensation. You
can apply this in any of theCreative Zone modes; some
cameras let you use it even
when you’ve set the camera to
Manual and have Auto ISO on.
On high-end EOS cameras,
you can set the compensation
by turning the large quick
control dial on the back of the
camera – to the right to make
things brighter, to the left to
make the image darker. Some
EOS M cameras have a
dedicated exposure comp dial
on top of the camera. Most
entry-level Canons require you
to press the ‘+/-’ button, then
rotate the main dial, but if your
camera has a touchscreen, you
can just slide your finger along
the scale there. Here’s the
thing: before coming up with an
exposure, Evaluative metering
has already basically applied its
own compensation, taking into
account the brightness, colour
and focus info.
The other metering modes
don’t do this, so you’re likely to
need more substantial
adjustments in these modes.E
R
Shadow Mid-tones Highlights
There’s lots of space on the left, so using minus exposure comp to
shift the histogram left we can rescue the highlightsShadow Mid-tones Highlights
The Canon Magazine 63
CORRECT EXPOSURES
Overriding the meter
Combine Evaluative metering with exposure comp
As^ shot^
+^1 2 /^3 EV^ (Expo
sure^ Value)^
I’ve focused on the birds
here, but the camera
wants to make the bright
sky a mid grey toneDialling^ in^ some^ p
ositive^exposure^ compen
sation^ corrects^this^ for^ the^ subse
quent^ shotExposing for the highlights
How to avoid burning out bright areas in exposures
ather than being a
selective adjustment,
exposure compensation
affects the entire image.
So, if you increase the exposure to
lighten the shadows in a picture
then you’ll brighten pale areas of a
shot too – and there’s a risk that
you may overexpose, turning them
pure white and featureless.
While it’s fine to ‘blow out’
highlights on shiny objects, you’ll
likely want to retain some detail in
other areas. You may have heard
photographers talk about
‘exposing for the highlights’; this
means adjusting the exposure to
ensure the highlights aren’t
overexposed. This may result indark areas becoming black and
featureless, but it’s usually more
preferable than burnt-out whites.
To keep track of how your
exposure adjustments are
affecting the image, check the
histogram. If the histogram shape
is being ‘clipped’ at the right, it
means that some of the bright
areas are being overexposed.
Dialling in minus exposure comp
will reduce the exposure, with the
histogram shifting to the left.
Shooting Raw files gives you more
options. Not only do they hold
more picture info than indicated
by the histogram, you can push
and pull the exposure (within
reason) in post-processing.Although Evaluative
meters the whole
scene, it biases its
exposure towards
the active AF pointEXPOSURE COMPENSATION