AV News 200 - May 2015
For some subjects, especially those with a very high contrast range there may
be no such thing as a single 'correct' exposure. In such circumstances the
photographer needs to decide
which part of the scene is most
important, and which method of
metering to use. The Gossen
Lightmeter image on the preceding
page was taken using an incident
light reading of f5.6 at 125th Sec at
100 ASA (ISO), this exposure
required
no
post
exposure
correction whatsoever, although it
was given approximately 3/4 stop
more exposure than indicated by a
camera TTL meter. Reflected
meter readings can be influenced
by the brilliance of background,
whereby an incident reading
completely ignores this. Adobe
Photoshop can rescue some
awkward exposure situations using
quite remarkable correction' tools.
Gaining access to the 'Exposure Correction Tool' in Photoshop is via the
main menu. Select Mode, then Adjustments, whereby another panel of options
spring to life. On this panel choose
Exposure. Clicking Exposure causes a
small and simple looking control panel
to pop up containing three slider bars
entitled 'Exposure', 'Offset', and
'Gamma Correction'. By default the top
two slider bars are set central indicating
zero in their numerical boxes, the
bottom slider bar 'Gamma Correction' is
also set central but as you may expect indicates a Gamma reading of 1.00. At
the top of this control panel sits a drop down menu entitled 'Preset' which is set
to 'Default' when first opened. Within this
drop down menu sits a pair of tiny
arrows, clicking on those arrows opens
up a drop down menu containing several
Presets i.e. Minus 1 stop exposure,
Minus 2 stops exposure, Plus 1 stop
exposure and Plus 2 stops exposure.
There is also a choice to select 'Custom'
whereby you can customise the amount
of stops either over or under exposure to suit your own requirements. To the
right of the drop down menu sits a 'Gear' shaped icon, clicking this icon allows
you to 'Save a Preset', Load a Preset', or 'Delete the 'Current Preset'.
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