In a comment on a Fossil of the Week post last month, Wooster Geologist Alumnus Dr. Bill Reinthal asked if I could describe how we do our lab photography in the Earth Sciences department. I started what will be a three-part series last week with a post on our macrophotography equipment and techniques. You may want to read that post first for our general photographic processes. Today I’m showing our photographic system that uses a dissecting microscope with reflected light. Later we’ll have a post on our microphotography through a petrographic microscope using transmitted light. As I wrote last time, I am not a professional photographer, and my other departmental colleagues do plenty of their own photography. I’m the one who tends to write the most blog posts! (This is entry #1109 for me …)
The above image is of a limestone bedding plane from the Carmel Formation (Middle Jurassic) of southwestern Utah. You can see most of the grains are carbonate ooids, with a scattering of crinoid (Isocrinus nicoleti) debris, including a beautiful star-shaped columnal. (The high-resolution version can be found here.) This image was made with the equipment described below. The scale bar was added later using Adobe Photoshop.
This is our dissecting microscope photographic system. On the left is a fiber-optic gooseneck lamp with two light tubes. The tube on the left is closer to the specimen to produce a dominant light source from the upper left (a paleontological convention to ensure uniform shading). The fiber-optic tube on the right is farther away from the specimen so that it provides a softer fill-in light to brighten the shadowed areas. These are easily moved for various lighting effects depending on the specimen. The microscope in the middle is a Nikon SMZ 1500 with a Lumenera Infinity 3 camera attached in the upper right. The camera taps into the microscope’s light path, so you don’t need to use the eyepieces. The Mac computer on the right is running the Lumenera Infinity photographic software. Our ace geological technician, Nick Weisenberg, has written detailed instructions for using the software with ease.
The Nikon SMZ 1500 microscope has a built-in aperture, which should be closed down as far as possible to get the best depth-of-field.
The camera works very well. We also have versions 4 and 5 attached to petrographic microscopes.
That’s it for this dissecting microscope photographic system! The images it makes are excellent. We spend most of our time composing the scenes and constructing the scale bars. Two more example photographs are below.
This is olivine sand from a Hawaiian beach. (The original is here.)
This photographic system is used often by Dr. Greg Wiles and his tree-ring lab students. It works especially well with sanded tree-ring cores, which are essentially two-dimensional. Layali Banna (’22) made this evocative image last week.
These three entries on our laboratory photography systems (macrophotography, microphotography part 1, microphotography part 2) are designed to show our current and future students what we can do in our department.
Wonderful, Mark–nice of you to include a full pentagonal columnal on this photo!
People should be encouraged to experiment–there’s a lot of inexpensive, but good, equipment available on sites like eBay, but some of it is just plain bad. With optics, unfortunately, quality means big $$$ (at least for new equipment), and without the extremely high quality lenses, in the optical pathway, there ends up being both chromatic aberration (prism effects), and worse, spherical aberration (impossible to keep edges and center of field in focus). One of the advantages of photo-microscopy is that phone cameras often can do a very good job, simply handheld above one of the oculars on an inexpensive low-power microscope. It’s great for minerals, flowers, tiny critters (including cicada wings), and anything else just beyond our eyesight’s capabilities.
For your readers who love peridot (olivine), and have the opportunity to go to HI, the most famous “green sand beach” is on the extreme SW corner of the Big Island, in a state park there. People aren’t supposed to collect it (incurring Pele’s wrath if they do), but it’s so much fun to dip your hands in large piles of tiny, weathered-out, grains of beautiful olivine! If they can’t get to the Big Island, the best place to find olivine is on the San Carlos Apache Reservation in AZ. There, what are probably mantle xenoliths (Dr. Pollock would know better than me) of big, fist-sized, inclusions of olivine, in the basalt flows, are actively quarried and distributed worldwide, and occasionally, gem-quality material is liberated from the material.
Thank you for taking so much time to write all of this up for your blog (and for the great photos, too)!
Thanks for the excellent, detailed comments, Bill. They increase the value of our posts with additional ideas and information. One more photography entry is on its way!