then set –1 exposure compensation. If you need
the scene to be a little lighter, then set +1 expo-
sure compensation.
Exposure compensation isn’t some sort of photo-
graphy magic; the new exposure settings come
from the camera adjusting the current settings,
and this adjustment can have unforeseen conse-
quences. If, for example, you decide that the
image needs to be a little brighter, then the cam-
era will use either a longer shutter speed or a
wider aperture because that’s the way to get more
light to the sensor and make the image brighter.
This means that the shutter speed might drop,
causing a moving subject to be blurry or the
depth of field to become much shallower.Combining multiple exposures
One reason to take multiple exposures is to make
sure you get the best exposure for the scene, but
there is another reason to take multiple exposures —
to combine the images into a single image. To do
this, you need an image-editing program, such as
Adobe Photoshop or Adobe Photoshop Elements,
which allows you to import multiple images and
combine them into a single image. One of the more
common uses of combining multiple exposures is to
manually combine the images to create a composite,
as shown in Figure 2-16. This image was created
from combining Figures 2-13, 2-14, and 2-15. I
used the sky from the first image (Figure 2-13), the
water from the second image (Figure 2-14), and
parts of the ship from the third image (Figure 2-15).
I did this by putting each image on its own layer and
masking out the areas that needed to be hidden.allows you to make sure that the aperture and the
depth of field do not change in the bracketed
images.
When you use the shutter speed priority mode,
you set the shutter speed and the camera sets the
aperture. When you set the bracketing in this
mode, the camera first picks the aperture that it
determines is the correct exposure, and then it
picks the apertures that will under- and overex-
pose the image. This way, you can make sure that
the image has the shutter speed you want, but the
depth of field will be different for each shot.
Exposure compensation
Another way to quickly change the exposure of
your image is by using exposure compensation.
Exposure compensation is a camera function; not
all cameras have this feature, so check your man-
ual. The idea behind exposure compensation is to
purposely over- or underexpose the image by a cer-
tain amount, no matter what the camera deter-
mines the settings should be. The camera first
picks the settings that it has determined are correct
based on the built-in light meter and the metering
mode. Then it sets the values for the shutter speed
and/or aperture, depending on the exposure mode.
Finally, it adjusts those values, depending on the
exposure compensation you picked.
This makes it very easy to quickly make a photo
lighter or darker without having to actually set the
camera to manual mode and adjust the exposure.
Exposure compensation is set as a relative amount
from the proper exposure value, which is 0. So to
overexpose the image, you use the exposure com-
pensation controls to set positive numbers, and to
underexpose the image, you set it to negative
numbers. It may be possible to set the exposure
compensation in parts of a stop, depending on the
camera. For example, if the scene is just a little
bright and you want to darken the whole scene,
While this isn’t a book about how to
edit your photos in image-editing
software, combining images like this is covered in
Chapter 11 in more detail.x-ref