Dark-Field Illumination in Photography of Acetate Peels

Acetate peels of polished and etched surfaces are widely used, both in carbonate petrology and in paleontology. However, it is difficult to reproduce them photographically for publication. The most frequently used method is to project the acetate peel through a photographic enlarger. Generally, this results in a low-contrast negative print which is unsatisfactory for publication. There is also a limitation in the size of peels which can be uniformly illuminated using this method. The diameter of the condenser in the enlarger should be at least 1.5 times the maximum dimension of the peel to ensure even illumination and contrast.