Case Study—A Part Opaque and Part Transclucent Material
The mineral we are photographing here has a part that's rocklike and a part that's translucent crystal. It's almost as if we're photographing two separate subjects.
The assignment is to photograph a mineral that is part translucent and part opaque while retaining detail and showing the character of each part.
The mineral is positioned sideways against a black background with the crystal part facing up. The camera is positioned to shoot it head on.
One light is set up behind the mineral to backlight the translucent crystal and cast the shadow in front of the mineral. It also creates a graduated light on the background. A second light is set to the side of the mineral and adjusted so it's light sweeps across the opaque surface to show off the detail with sidelit highlights and shadows. It's facing down so just the edge of its cone of
light sweeps the surface of the mineral. If it were pointed at it more directly, the mineral would be overexposed.
3. Camera Settings
The only concern is exposure so a variety of images were taken as the second light was moved. It is trial and error that finds the ideal position, where the light from the two sources is properly balanced for the best exposure. The histogram is checked periodically to be sure we are not loosing detail in the highlights and shadows.
The setup contains a background sweep and two lights. One light
illuminates the crystal and creates the shadow in front of the mineral. The other lights the opaque surface of the mineral from the side.
The light from behind not only illuminates the translucent part of the mineral, it also casts a shadow in front of it, giving it "weight". The second light sweeping
across the surface of the mineral, shows off the detail in the opaque portion.