understand the histogram and b) have persuaded your
camera to show it to you.
The dawn image (right) looking south along Loch
Lomond has the usual defect of dawn photos looking
south. The left hand side of the sky is burned out to
white: and even worse, the adjacent sky (burned out in
the blue channel but not the green) has a nasty unskylike
turquoise green. If I’d looked at it, the histogram would
have revealed this: the right-hand, light-tones end of
the graph is chopped off against the edge of the frame.
Actually, I did look at the histogram... This one’s made
from two separate images; and dates from when I
used to do panorama stitchups by hand, and the two
component photos had to have the same exposure.
These days I expose each of the component photos the
way they should be. Photoshop, which now does my
panorama stitchups with digital insouciance, sorts out
the diff erences in exposures.
Looking back at the cairn histogram, it’s not
underexposed to the point where the left hand end is
chopped off . So there is still full detail in the dark areas.
However, the blank at the right end suggests I could,
and maybe should, try it again with a longer exposure.
That would move the whole histogram to the right, for
a better colour range and more detail in the shadows.
That second version of the image has now been deleted:
I liked the way the off -white snow has caught the slight
golden tinge of the newly-risen sun. Just sometimes, the
human may know better than the histogram...
Level Headed
The image of Skiddaw (right) was taken with a telephoto
lens from the wrong side of the Solway. My excuse is, I
live on the other side of the Solway. The histogram shows
that it’s very low in contrast. As an unsophisticated
image manipulator, you’ll just hit brightness/contrast
and hope for the best... But the Levels command (CMD/
Control + L in Photoshop) hits you with a histogram.
By moving in the markers at either end (as per the red
arrows) you can give the image the greatest tonal range
possible without either burning out the whites or losing
detail in the darkest bits.
The resulting image and histogram are shown on
the right. You may or may not like the image. But the
histogram is a bit horrid! The jaggy gaps indicate the
loss of quality caused by stretching out the JPEG image.
Shooting in Raw format will be the way to overcome
that one – the subject of my third article in this series,
supposing the editor lets me go on that long.
I must have my histogram!
By default, your camera’s back screen shows you the
picture you just took. Hitting the up and down arrows will
give alternatives. There could be a version where blown-
out areas fl ash on and off – that one’s for unsophisticated
people who can’t hack the histogram. Further up or
down should give you the histogram, either alone or with
the image alongside.
Any photo editing software will already be showing
you your histogram, or will do so if you ask it nicely.
Because it’s a computer it needs to be cleverer than you
are – and it may show separate histograms in red, green
and blue.
So welcome to a future of hardly ever having wrongly
exposed photos ever again!
16 Outdoor focus | autumn 2018
So – what constitutes a proper camera?
This series of articles is aimed at writers who aren’t really
photographers but need to be. So you need a proper camera.
A proper camera has:
• A sensor 24mm wide (36mm is better than you need!)
• Lets you shoot in a semi-automatic exposure mode (eg
Aperture Priority), or Manual Exposure
• Can display a histogram, either in Live View or playback
• Will shoot in Raw format
Advanced compact cameras do it. A second-hand digital SLR
camera is cheaper, around £200, but heavy and cumbersome.
Next - White Balance, what it is and why you need to set it
correctly.