SUMMARYThe following method is proposed for the analysis of the elliptically polarized light leaving a transparent, birefringent and dichroic specimen (in which the direction of maximum absorption coincides with either of the principal axes of refractive index), oriented with its optic axis at ± 45° relative to the transmission azimuth of the polarizer.Between the specimen and the rotatable analyser are two λ/4 plates; that nearer the specimen is fixed with its slow axis at ± 90° to the polarizer, while that nearer the analyser is rotatable. If the amplitude ratio of the components of light leaving the specimen is tan Y (Y being less than 45°), and their relative retardation is Δ°, at compensation the azimuth of the rotatable λ/4 plate will be Δ/2 (relative to its initial position orthogonal to the polarizer) and that of the analyser will be (45° ‐ Y), relative to the new azimuth of the rotatable λ/4 plate.Apart from involving minimal calculations, the method is capable of high precision with suitable equipment, since all critical settings can be made with the aid of a Nakamura half‐shade plate. Although so far used only in transmission polarization microscopy, the method is quite general and could be applied in any work involving
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