Using a Filter


Filters
allow photographers to retain more control over the final result of
their images. Some produce subtle effects, whereas others are more
dramatic. In some cases, they actually help to create images that would
otherwise not be possible without them.


Photo by Andrea Hargreaves

Without filter

‘With
some landscape images you’re going to find that there is a drastic
contrast between the necessary exposures for your sky and foreground,’
says Tom. ‘When you’re faced with this situation, you need to apply a
filter – in this case, a graduated neutral density filter, otherwise
know as a split neutral density filter. With a graduated filter, half
the filter is neutral density. This means that half the filter is grey
and either reduces or modifies the intensity of wavelengths of light or
colours.’


Graduated neutral density filters are used to bring an
excessively bright part of a scene into balance with the rest of the
image. It can be used to darken a bright sky so that both the sky and
subject can be properly exposed. The easiest way to remember this is:
the greater the contrast, the darker the grad.

 

Photo by Andrea Hargreaves

With ND Grad

‘ND filters can
basically be split into two categories: hard and soft,’ explains Tom.
‘Hard and soft refer to the transition between the grey half and the
clear half of the filter. With a hard edge, the transition is abrupt and
is used when there is a distinct change in brightness levels, such as
in a picture of a field with a horizon line that splits the landscape
from a bright sky. A soft-edged filter is used when there is no clear
distinction between the light and dark portions of your image.’


Filters
are available in a range of intensities (how many stops down you want
to bring your highlights), ranging from 0.3 ND/1 stop to 0.9/ 3 stops.
Some manufacturers produce more advanced filters (including the famed
10-stop filter), but most photographers use 1-3 stops.


‘Sometimes
you may find yourself in a position where the intensity of the filters
you have aren’t quite up to the job,’ says Tom. ‘It may turn out that
you need a 4-stop filter. The easiest solution is to use two filters
together such as a 0.3 and a 0.9 filter. Of course, there’s always the
option to work on the image in Lightroom [as we’ll see later], but it’s
always better to get it right in-camera.’


A polarising filter
has two distinct uses: it can darken skies by filtering out the
polarised component of skylight, and it can remove reflections from
surfaces such as water.


‘I often use a polarising filter when
shooting foliage,’ says Tom. ‘Using the filter can actually reduce
reflections, which is something we wouldn’t commonly associate with
vegetation. If you hold up a polariser and look through it at some
leaves, you’ll see that the colours look incredibly fresh and saturated,
particularly in the greens. However, you should always remember to add
11⁄2-2 stops of exposure because you’re losing some light with the
filter on your lens.


‘People new to polarisers shouldn’t allow
the differences between circular polarisers and linear polarisers to
confuse them,’ adds Tom. ‘Visually, there is no difference between the
two. It’s just that they polarise the light passing through in different
ways. Circular types are best for any camera with AF.’

Pages: 1 2 3 4 5