The photography for the marbles on this site was done with a Nikon
Coolpix 4500. It has one of the best close-up capabilities of the
non-professional digital cameras. A Raynox macro lens by was used to accomplish the macro-type pictures. The
lighting was done with two Bowens Tri-light compact fluorescent
lights. Three 30-watt bulbs are housed in each light with a built-in
diffuser, giving bright, even, light when the units are close to the
subjects. They are color corrected fluorescents and emit very little heat.
The non-macro close-up shots were done with
the same equipment (minus the Raynox lens) and further diffusion was
accomplished with the RedWing cocoon. The cocoon is a plastic 'tent'
which houses the camera and subject. The lights are outside the tent,
which diffuses light entering through the plastic, creating a
very soft light.
The macro shots of marbles are difficult to
accomplish. Keeping the subject in focus is challenging when the
lens less than an inch from the subject, The depth of field is less than one
millimeter. (Depth of field is the total amount of the picture in focus.) This
presents a particular challenge for marbles, because a marble is a curved surface.
As the surface curves, it moves out of the field of focus. If a
marble were flat, the 1 mm depth of field would be no problem.
To give some idea of the difficulty
notice the small silverish white spots. These are very small balls
of silver used as one of the colorants in the Metal series. Some are in focus,
others are not. The larger the ball, the more it becomes out of
focus, because its height 'leaves' the field of focus of the 1mm
depth of field. The larger of these balls is approximately .025 of
an inch. Therefore the littlest silver balls within the trails
just right of center are very small indeed.
Adding to the difficulty is the process of focusing itself. This is a non-professional digital camera,
so you cannot focus by
turning the lens as with SLR cameras, or like a pair of binoculars.
You also can't focus through any
camera controls. Instead , either the camera or the subject has to
be moved in tiny steps until the focus is satisfactory. The color
surface is the point of focus, because there is a layer of
encasing glass around the whole of the marble, care must be taken
that the focus remains on the color layer and not on the outer, clear
glass, layer.
This would all be impossible if it were not for the aid of
a good tripod, and connecting the camera to a TV to view a very large image of the
subject before taking the picture.
To see more of this marble use this link.
#5 marble of the Metal series
The picture below is the Redwing cacoon and Trilite system mentioned
above.
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