Depth of Field
Depth of field refers to the zone of acceptable
focus extending in front of and behind the
plane of sharpest focus. As this zone is excep-
tionally shallow at high reproduction ratios,
previewing is desirable before
shooting.
To pre-
view, press the depth-of-field button on the
camera and the lens will close to the preselect-
ed aperture to allow you to see how much
background and foreground is in focus. Depth
of field can also be observed by reading the
color-coded indicators inscribed on the lens
barrel.
A pair of orange lines on either side
of the white distance scale index line corre-
sponds to f/32 which is the same color on the
aperture scale. At close distance, so little is in
focus that the depth-of-field tables on pages
13 ~ 14 are more useful.
NOTES ON FOCUSING
To avoid camera shake, close-up photog-
raphy poses several problems not encoun-
tered in general photography. One of these
is sensitivity to vibration: the magnifica-
tion of the image on the film makes even
slight image displacement prominent and
results in a blurred image. Therefore, for
best results, mount the camera on a tripod
or on rigid supports, and use a cable release
to trip the shutter.
At extremely close working
distances,
depth
of field decreases to the actual focused
distance. This can be partially compensated
for by stopping down the lens. But at very
close distances an extremely narrow depth
of field is inevitable. Careful placement of
the subject, if it has depth, will be neces-
sary to ensure that the important surfaces
will be in the same zone of sharpness.