A scaling device projects a known optical pattern into the field of view of a
camera,
which can be employed as a reference scale in a resulting photograph of a remote
object, for example. The device comprises an optical beam projector that projects
two or more spaced, parallel optical beams onto a surface of a remotely located
object to be photographed. The resulting beam spots or lines on the object are
spaced from one another by a known, predetermined distance. As a result, the size
of other objects or features in the photograph can be determined through comparison
of their size to the known distance between the beam spots. Preferably, the device
is a small, battery-powered device that can be attached to a camera and employs
one or more laser light sources and associated optics to generate the parallel
light beams. In a first embodiment of the invention, a single laser light source
is employed, but multiple parallel beams are generated thereby through use of beam
splitting optics. In another embodiment, multiple individual laser light sources
are employed that are mounted in the device parallel to one another to generate
the multiple parallel beams.
