18
Technique MYTHS BUSTED
17
Highlights can be
recovered in raw
Raw fi les have much greater
dynamic range than JPEGs,
making it possible to recover
extra shadow detail. But there’s far
less scope to recover highlights
accurately. Raw fi les do contain
some extra information, as the
individual colour channels all
clip to white at different points,
which means raw converters
can reconstruct some additional
tonality. But the moment the fi rst
channel has clipped, any colour is
at best an estimate. As a result,
pulling the brightness or highlight
sliders back too far will result in
false colours or posterisation. So
it’s best to avoid highlight clipping.16
MicroFourThirdscameras
give deeper depth of fi eld
Smaller formats give deeper DoF for a given angle
of view and aperture setting; hence you might infer
that Micro Four Thirds cameras can provide deeper
front-to-back-sharpness than APS-C or full-frame
models. But the problem is that diffraction blurring
also impacts smaller sensors more. In fact DoF and
diffraction scale in precisely the same way with sensor
size, so you can get exactly the same DoF on larger
sensors by stopping the aperture down further.12
More pixels bring lower dynamic range
With smaller pixels being individually noisier, it appears to stand to
reason that higher-resolution sensors will show lower dynamic range. But for
much the same reason as with noise (see myth 20), this isn’t necessarily true.
What really matters is that the sensor maker keeps the electronic read noise
very low, which is the case with the latest round of high-quality 40-50MP
full-frame sensors. As a result, they show extraordinary dynamic range.13
Only shoot raw
One of the fi rst things
enthusiast photographers are told
is that raw fi les give the best image
quality, and should be used all the time.
The implication is that you’re not doing
proper photography unless you sit at
home after the event post-processing
and fi ne-tuning your masterpieces. But
cameras now make better JPEG fi les
than ever before, which are perfectly
usable in many situations. For family
snaps or casual shooting, JPEGs are
fi ne (although it still makes sense to
shoot raw fi les alongside, just in case).
With most cameras, turning off raw
greatly extends buffer depth when
shooting bursts, increasing your
chances of getting the perfect shot.
15
Always set the
highest-quality JPEG
One of the earliest things we learned with digital was to
always select the highest-quality JPEG setting. Otherwise,
there was a risk of getting compression artefacts across
blocks of pixels, especially on subjects with diagonal lines.
But since then, camera makers have adopted visually
lossless processing that gives no obvious artefacts. However,
some have gone even further and included ultra-low
compression options that, while technically more faithful to
the original scene, aren’t visibly better. Usually they’re turned
off by default and there’s no need to enable them, as they
take up more card space and slow down the camera.14
A shutter speed
of 1/focal length
will avoid shake
This is a rule of thumb that worked
pretty well with 35mm fi lm, but it
doesn’t translate so well to digital.
Crucially, you need to take sensor size
into account and use equivalent, rather
than actual, focal lengths. So with a
50mm lens you might choose 1/50sec
on full frame, 1/80sec on APS-C and
1/100sec on Micro Four Thirds. What’s
more, if you want to be confi dent of
getting pixel-sharp results in every
shot, you’ll probably want to use shutter
speeds a stop or more faster. On the
other hand if you have a stabilised
camera or lens, you’ll be able to use
slower speeds, but at the risk of blur
from subject movement.
Sony’s 42.4MP
full-frame sensor
records a vast
dynamic range
Sony RX1R II, 35mm f/2,
0.4sec at f/2, IS0 100Avoid using small
apertures on Micro
Four Thirds cameras
Olympus E-M5 II, 50mm f/1.8,
1/50sec at f/11, ISO 200Excessive highlight
recovery from raw
has resulted in the
blue sky turning grey
Sony Alpha 7R III, 24mm f/1.4,
1/400sec at f/1.4, IS0 100