panoramic photographs
The extra shadow or highlight details captured in this additional sequence can be added to the
images in the fi rst sequence using layering techniques in your image editing software. These tonal
composites can then be used for the stitching process. To ensure that you have suffi cient picture data
in scenes with extreme brightness changes you may need to capture three complete sequences with
varying exposures. The exposure for one sequence should be adjusted to record highlights; one for
shadows and if required a third can be used to capture midtones. You can even use your camera’s
exposure bracketing system to shoot the over-, mid and underexposures automatically.
- Don’t adjust the focus or zoom
A similar problem of differences from image
to image can occur when your camera is set
to auto-focus. Objects at different distances
from the camera in the scene will cause the
focus to change from shot to shot, altering the
appearance of overlapping images and creating
an uneven look in your fi nal panorama. Switching
to manual focus will mean that you can keep the
point of focus consistent throughout the capture
of the source images. In addition to general focus
changes, the zoom setting (digital or optical) for
the camera should not be changed throughout
the shooting sequence either. - Determine the ‘depth of fi eld’
Despite the fact that cameras can only focus on
one part of a scene at a time (the focus point)
most of us have seen wonderful landscape
images that look sharp from the nearest point in
the picture right through to the horizon. Employing
a contrasting technique, many contemporary
food books are fi lled with highly polished pictures
where little of the shot is sharp. I’m sure that you
have seen images where only one tiny basil leaf
is defi ned whilst the rest of the food and indeed
the plate is out of focus. Clearly focusing doesn’t
tell the whole sharpness story.
This phenomenon of changing degrees of
sharpness in a picture is referred to as the
‘depth of fi eld of acceptable sharpness’ or ‘DOF’.
When shooting panoramas source images it is
important to know the factors that control this
range of sharpness and, more importantly, how
to control them.
Switch your camera to manual focus and then
set the distance to encompass the subjects in
the scene taking into account ‘depth of fi eld’
effects as wellEnsure that you consider focus and depth
of fi eld at the same time, as both these
variables will affect the subject sharpness in
your source images.
(a) Sharp foreground detail.
(b) Background unsharp due to shallow DOF