文档介绍：depth _ 87
scale
just as with depth and distance, the physical
size of things can be difficult to tell from a
photograph alone. For this reason, it can be
helpful to provide some sort of scale object that
gives the viewer an idea of just how big, or how
small, the subject really is.
Of course, this is not necessary with all, or even most, subjects.
Many of the things that we photograph are sufficiently familiar
to every viewer to ensure that they don’t need any guide to their
size. For example, if you see a picture of a still life, you make
automatic, and fairly accurate, assumptions about the size of
the bottle of wine and the apples that have been arranged.
When photographing less familiar objects, it can pay to
provide some way for the viewer to gauge the proportions of what
they are seeing. In scientific photography, such as might be used
on an archaeological dig, the solution is simply to lay a ruler
beside the subject that is being documented, and include this
within the frame. In artistic and everyday photography,
a more subtle approach is called for.
In order not to ruin position, a subject of a known
size is used to act as a parison. People are frequently
used, for example, to provide a sense of scale to a rock formation
or a building. This is particularly useful if the subject is
unusually large—you can reveal the true height of a tower
more easily if you can see antlike people on top of it.
However, it is important to realize that this trick only gives
a general idea of scale—and can be used pletely mislead.
You can only judge the size of one pared to another
if they are the same distance from the camera—otherwise the
farther one will look smaller because of perspective. If you put
the person significantly closer to the camera than the main
subject, then it es much harder for them to be used as a
scale. However, you may not be able to pick out a passer-by who
is close enough to the buildin