Fine scale models pose a
special problem for photographers.
Because of the small size of the models and the relatively long focal
lengths of even the finest 35 mm cameras, serious modelers who also
wanted photographs of their craft in focus were forced to spend
hundreds or thousands of dollars on expensive macro photographic
equipment.. Nothing ruins the illusion of reality like a photograph
out of focus due to optical limitations. With a $2000 macro APO lens,
bellows, medium format bodies and other expensive devices, this
problem can be eliminated. However, most modelers do not have the
expertise or need for such investments.
For only $8.49 on a throwaway camera,
pocket change for sheet
plastic, and with a little ingenuity, you can take a photograph of
the
entire model/diorama with every detail in focus with little or no
distortion. Saving money and avoiding the need for advanced
photographic skills is what this camera modification is about.
With award winning photographs
the illusion of reality and
creativity is key. We took pictures of a TBM Avenger and SBD
Dauntless from six inches away, and our colleagues believed we went
to an airshow and photographed the real thing. If you look closely
you can see the air conditioner and house in the background. We
achieved this result using our pinhole camera.
In the August 1999 issue of Popular
Photography, Dr. James
Fite discovered a process of modifying a Kodak panoramic disposable
camera. We have applied his techniques and have come up with a
slightly better method of achieving remarkably clear results through
some modifications of our own. But before describing the process of
building the camera, it would be helpful to know a little about what
a
pinhole camera is and why it works as good as really expensive
lenses.
The principle behind the camera
is simple: the smaller the
opening through which the light passes, the longer the "depth of
field." This means that a really small hole can give you a photograph
that is in focus from a mere inch to infinity. (There are some
limitations on this principle for very small holes because of
diffraction. See technical discussion section for advanced theory if
interested.) The opening in the diaphragm of a lens is called the"
f-
stop" or aperture. Most cameras have user adjustable or automatic f
stop control from about f1.2 to f22. The larger the number, the
smaller the aperture size. Thus at f16 more objects are in focus than
at f1.2. The principle here is: at large lens openings depth of field
decreases. For example, if you focus on a object 12 feet away,
everything from 7 to 25 feet is in focus at f16. If you focus on the
same object at f1.2, only those objects from 11'11" to 12'2" are in
focus.
The second principle
of photography is this: The smaller the
hole the longer the exposure. With a really small aperture, you could
spend several minutes to hours getting enough light onto the film to
get a correct exposure. Modern cameras are a compromise between
these two principles. Faster shutter speeds makes hand held point
and shoot photography possible because it minimizes the natural
shaking of the hands. Faster shutter speeds demand larger lens
openings which reduces depth of field. Under most conditions it is
not practical to have an f-stop smaller than f16, because anything
smaller increases exposure time and most photographers do not need
infinite depth of field. Thus, most mass market camera makers
compromise shutter speed, focal length, and aperture.
These compromises pose unique problems for the scale
modeler. To take a conventional photograph of a 1/48 scale model
from a close enough range to see the detailing, you sacrifice the focus
on most of the model. Our modifications will solve this kind of photographic
problem.