Getting to grips with bracketing
I understand the concept of
bracketing exposures and I'm beginning to see the benefits, but can I get my
camera to do it successfully? Can I heck. Help!
Getting
to grips with bracketing to get the best pictures
For those who aren't familiar with
bracketing, it involves taking several shots of the same subject or scene, but
varying the exposure for each to ensure that one of them will be perfectly
exposed. In this digital age, where a fair degree of exposure error can be
corrected during post-production, you might think that there's no longer a need
for bracketing. However, it's always better to get the exposure correct
in-camera rather than to rectify mistakes later, so bracketing does still have
its place.
There are three ways to bracket with your
DSLR. The first is to use the Auto Exposure Bracketing (AEB) feature that
you'll find in your camera's menu. With most cameras this works in all exposure
modes except Full Auto and allows you to set the parameters of the bracket; how
much over and under the correct exposure you want to bracket, usually up to +/-
2 stops in 73 stop increments. With some DSLRs, you can also set how many
frames you want in the bracket (usually three or five). For example, you could
set AEB to -1 stop, 0 and +1 stop, or -2,-1,0, +1, +2 stops - depending on the
situation. Many DSLRs also let you shift the bracket either side of the
'correct' exposure to cope with extreme lighting.
The main thing to remember with AEB is that
if you have your camera set to single-frame advance, you need to press the
shutter button three times (or five) to complete the bracket. If you don't,
you'll only take the first frame in the bracket, then if you change camera
position, the next shot you take will be the second one in the AEB sequence,
which could be totally wrong for that situation.
To
get the best effect on the clouds they used auto bracketing -1, 0, +1, then
combined the shots in photomatrix
If AEB sounds complicated, you can bracket
using exposure compensation by taking a shot at the metered exposure (ie with
compensation set to 0) then bracket frames over and under that. This method is
quick and efficient once you're used to it because you can bracket as many or
as few frames as you like and the bracket can be customised to suit each
situation. You can again use exposure compensation in all exposure modes except
Full Auto.
The final method is to set your camera to
manual mode so you have to set both the aperture and shutter speed. If you
choose an aperture and shutter speed combination to get the correct exposure,
to bracket exposures all you do is adjust either setting (or both) to increase
or reduce the exposure. If you're not used to manual mode you may find this a
little fiddly, but it does offer complete flexibility to bracket exposures
however you like.
