Polyfocal photography of conodonts and other microfossils using petrographic microscopes

Polyfocal photography is a method for obtaining digital images that have great depth of focus. A series of photos are made at successive focal levels from the bottom to the top of a fossil using reflected light. Computer software takes the part of each image that is in focus and merges all of the parts into a composite image that is entirely in focus. Microscopes designed for this purpose are available but are expensive. A petrographic microscope with a digital camera can produce such a series of images, and they can be composited by an inexpensive computer program. Polyfocal photography appears to be superior to other methods of photography for illustrating conodonts. Composite images show internal features, such as basal cavities and white matter, and the software can convert one composite image into a stereoscopic pair.