Abstract

This microscope, intended primarily for photography with transmitted or reflected light, and particularly at high powers, departs widely from conventional design, especially in massive structure, appropriate materials, and high precision. Its most novel part is the motor-driven fine focusing mechanism which is 100 times slower than on standard instruments; 1 scale division = 0.01 micron or 100A. With this precise control of focus and with material for investigation believed superior to any hitherto employed for testing lens quality, results are secured and illustrated which indicate that true depth of focus is substantially less and resolution substantially greater than current theory would permit. Thus, change of focus of 1000A can be plainly recognized; and a colored structure 1070A wide is revealed in a photograph at 3175 diameters. It is inquired whether existing microscopical theory may not need review. Since present lenses apparently surpass their theoretical limits, a plea is made for better lenses still.

© 1937 Optical Society of America

An Examination of the Principles of Orthostereoscopic Photomicrography and Some Applications

L. C. Martin and T. R. Wilkins
J. Opt. Soc. Am. 27(10) 340-349 (1937)

A High Speed High Precision Microphotometer

H. B. Vincent and R. A. Sawyer
J. Opt. Soc. Am. 27(5) 193-197 (1937)

On the Precision of Photometric Observations

Alfred H. Holway
J. Opt. Soc. Am. 27(3) 120-123 (1937)

Experimental Determination of Photographic Density*

A. M. Koerner and Clifton Tuttle
J. Opt. Soc. Am. 27(7) 241-256 (1937)

A Direct Reading Comparator for Spectra

L. G. Hoxton and D. W. Mann
J. Opt. Soc. Am. 27(4) 150-154 (1937)