Abstract

Exception is taken to the classification of optical instruments by the signs of their powers, and an alternative division comprising five classes is proposed, based upon the separation of the four Gaussian constants into two groups according to their signs. This classification cannot be modified by the addition to the system of inverting prisms and the like, and the properties usually associated with the sign of the lens in reality depend upon its class according to the new system. Each class may have systems of positive or of negative power.

© 1922 Optical Society of America

Aeronautic Instruments

Franklin L. Hunt
J. Opt. Soc. Am. 6(7) 744-811 (1922)

The LensometerAn Instrument for the Measurement of the Effective or Vertex Power of Ophthalmic Lenses

Charles Sheard and E. D. Tillyer
J. Opt. Soc. Am. 6(10) 1030-1039 (1922)

The CrystelliptometerAn Instrument for the Polariscopic Analysis of Very Slender Beams of Light

Le Roy D. Weld
J. Opt. Soc. Am. 6(1) 67-91 (1922)

The Beginnings of Optical Science1

James P. C. Southall
J. Opt. Soc. Am. 6(4) 293-311 (1922)

On the Characteristics of Optical Systems for Reading Small Mirror Deflections

G. W. Moffitt
J. Opt. Soc. Am. 6(5) 494-499 (1922)