A method of dark-field and simultaneous light--dark-field illumination for photomacrography of autoradiographic preparations.

A technique is described for dark-field and light--dark-field illumination of autoradiographic preparations for photomacrogra. A right-angle prism is employed as a substrate through which illumination is introduced to the specimen. The technique permits uniform illumination of large fields of view, and also minimizes the image-degrading effects of chromatic dispersion and excessive noncoherent scatter which are often associated with conventional dark-field illumination.