EXPAND TONAL
RANGE IN RAW
In his continuing series of Digital Darkroom articles,
Jon Adams explains how to capture the full brightness
range of a scene in multiple shots, and then blend them
together in Photoshop CC as an HDR image.
T
he dynamic range (DR)
of a scene extends from
the brightest to the
darkest areas that still
reveal some detail. On scenes
with a very high dynamic range,
it’s not possible to capture the
whole range in a single exposure,
because a digital camera’s sensor
simply can’t do it. With a scene
which contains a bright sky and a
dark foreground, you can set the
exposure to record details in the
brighter highlights but which will
throw the shadows into obscurity.
Alternatively, you can add more
exposure to record the shadowdetail, but which will then blow out
all the bright areas to pure white.
To get the best of both worlds,
you can shoot multiple exposures
to record detail across the entire
tonal range, and then blend them
together to create a high dynamic
range (HDR) image. This gives a
picture that’s closer to the way
the human eye would perceive
the scene, as the eye can take in
a much bigger dynamic range than
a camera.
RAW fi les already possess
a wider dynamic range than a
standard image fi le format like a
JPEG, and this extra detail can berevealed by adjusting the settings
in a RAW converter such as Adobe
Camera RAW or Lightroom.
A recent addition to this
software’s engine allows you
to shoot multiple exposures at
different values and then combine
them together to get a special,
HDR RAW fi le. You then process
this just like any other RAW, and
use the expanded dynamic range
present to create striking images
that retain a natural look. So let’s
look at how to set up your camera
to capture a multi-exposure HDR
sequence, and how to process the
shots in Adobe Camera RAW.DIGITAL DARK ROOM
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