20 29 June 2019 I http://www.amateurphotographer.co.uk I subscribe 0330 333 1113
frame and average them
out to produce a correct
exposure. However, metering
systems can be deceived,
particularly with back-lit
and high-contrast scenes or
when you shoot a light subject
against a dark background
or vice versa. You can consult
your histogram and apply
exposure compensation (see
box) to correct errors. But for
accuracy, try spot metering.
Spot metering allows you to
expose for a tiny portion of the
frame (typically 1-4%), without
light, contrast or darkness in
other areas infl uencing the
result. Unless you are adjusting
settings manually, you may
need to ‘lock’ exposure when
spot metering to prevent
settings from changing if you
recompose. Most cameras have
an Auto Exposure Lock (AE-L)
button on the back (or a button
you can customise to do this)
which allows you to lock
exposure settings until you
press the button again.
Achieving consistently
correct exposure is no dark art,
and modern cameras make our
lives relatively easy. But correct
exposure extends far beyond
the process of capturing
light accurately. Once you
understand it, you can expose
creatively – creating dramatic
silhouettes by underexposing
subjects, or high-key results
by making shots brighter.
Exposure will infl uence the
mood of your shots. Light,
bright images will convey a
positive vibe, while dark shots
tend to be more dramatic. You
can imply subject motion by
using a long exposure to blur
movement. Or you may wish
to generate a fast shutter speed
to suspend action. Anything
is possible once you’ve
mastered exposure.Technique EXPOSURE MASTERCLASS
Exposing to the right
- is it still relevant?
ETTR images look washed out on the LCD, but capture more tonal detailEXPOSING to the right (ETTR) is a raw-only exposure technique,
where you push exposure to the right of the histogram as far as
possible, without any clipping occurring. Technically speaking, you
are overexposing the fi le, but without actually sacrifi cing any highlight
detail. It is best to do this in conjunction with your live histogram,
applying positive compensation incrementally until you see the
brightest pixels nudge up to the far right of the graph.
But why would you deliberately expose incorrectly? Well, sensors
are linear devices and they capture more tonal information – and less
noise – in the brightest stops. Although ETTR images will look bright
and washed-out on the back of the camera, during processing you
can adjust the black & white points, contrast and overall exposure to
produce a natural-looking, correctly exposed result.Bigger, cleaner fi les
ETTR images tend to be bigger, cleaner fi les as they are capturing
more data, and should possess smoother tonal transitions. As a result,
they will reproduce better. However, it is fair to say that ETTR is less
important than it once was. The latest generation of cameras capture
more tonal levels and have cleaner shadow detail. Therefore, while
it is still good practice to avoid underexposure, raw fi les tend to be
more forgiving now. I don’t obsess over ETTR, but when practical, I do
push my exposure to the right – it makes sense to maximise quality.
However, ETTR isn’t a technique you can easily apply to all subjects.
For example, when photographing action, like wildlife, you will rarely
have time to be so precise with your exposure. Lengthening exposure
is also rarely practical when photographing moving subjects or
shooting handheld. In other words, expose to the right when possible
and appropriate to do so, but don’t panic if it is not practical.Exposed to the right – raw fi le
Final processed image
Marbled white butterfly.
Backlighting can deceive
your camera’s TTL
metering. When possible
use your camera’s live
histogram to achieve the
correct exposure
Nikon D850, 200mm, 1/600sec
at f/4.2, ISO 1600