Technical Information

I take my photographs with an Olympus E330 SLR camera, using the Zuiko 50 mm macro lens. I generate nearly all of my mineral images using CombineZM. In addition to extending the depth of focus, this enables me to use the aperture at which my lens performs best (5.0). With the lens alone, I can achieve a minimum horizontal field of view of about 4 cm; with a ring extender, I can reduce this to 1.8 cm. Images are captured in RAW format and currently, I process these entirely with Photoshop.

Images generated with CombineZ are much more detailed than single-frame pictures, but they have the disadvantage of having fewer of the visual cues that allow the viewer to appreciate the depth of view of the scene. On balance, I find this tradeoff more than satisfactory but I do try to leave the rearmost portion of the image out of focus, to retain some of these cues. I have found that using a frosted black acrylic sheet as a background is helpful in this regard; it has just enough fine detail to be clearly in or out of focus, but not so much detail that it distracts attention from the specimen. Recently, I have begun using the stereo image pair generating feature of CombineZ. The stereo images are not of much use for display, but would be very useful as aids for learning crystallography. Here are some examples 1 2 3 4 5. Email me if you have an interest in stereo images.

I use a home-made apparatus to photograph in, which doesn't much resemble any setup I've read about. A bank of 8 50 watt halogen lights is directed upward at an arcuate hood lined with crushed aluminum foil; beneath the lights and about 30 cm above the specimen is a sheet of frosted transparent acrylic. Small pieces of black cardboard, placed on top of the acrylic sheet, allow me to selectively shade some areas to eliminate or reduce extreme reflections. In many cases, and especially for glassy or metallic specimens, I find placing sheets of paper towel over the acrylic useful to create an extremely even, diffuse light source. All of these elements are mounted within a wooden frame spray-painted flat black to eliminate all but overhead light. Small white or aluminized cardboard reflectors, angled towards the specimen from the surface or from attached wires anchored to vertical segments of dowel (painted black!), provide for fill lighting and control of specific reflections. Exposure times are typically about 1 second but may be as great as 3.2 seconds.

I have posted over 1000 pictures at mindat.org, and I would encourage you to visit my user page there to see many examples of my work. Many of my photos have been Picture of the Day on mindat.