A method of strengthening Al film on reflecting mirror is described. First, for cleaning the surface by electron bonbardment, electrodes of various shapes are tried and their effects are examined by the luminescence of fluorescent substance applied in advance on the surface. To prevent the peeling off of Al film, SiO is deposited as the first coating. SiO is again deposited over Al for protection against mechanical and chemical attacks.
For steel, chrome plated brass and glass that were polished by Al2O3 powder or emery paper, log I-i curves and intensity of specularly reflected light in the vicinity of critical angle are obtained by means of a goniophotometer (Fig. 1), where I is the intensity of reflected light and i the rotating angle of the specimen. Log I-i curves beyond the critical angle show strongly reflected light (R component) only in the vicinity of specular reflection. This R component is considered to give “Sheen” phenomena. The intensity versus angle curves for specularly reflected light are obtained for the vicinity of critical angle, giving a break at critical angle in each case.
A. Walsh devised a multiple pass monochrometer of high resolving power with least effect of scattered light. On this principle, a double pass infrared spectrophotometer using a con-venient optical system has been constructed. To match the time constant and the output of the thermocouple, the chopping frequency is set at 5c.p.s. The resolving power is about 1.5cm-1 at 10.5μ and about 2cm-1 at 6μ.
Studies on color reproducibility of coated photographic objectives for the color photography are given, taking into consideration of the fact the maximum sensitivity of the blue sensitive emulsion of color film lies in ultra-violet region. Colorimetrical calculation and experiments show that the color of reflected light from coated objectives which give the most faithful color reproduction is, generally speaking, purple for the objective of F-ratio lies between 3.5 and 4.5, magenta for 2.8_??_2, and amber color for 1.8_??_1.2, according to their degree of ultra-violet absorption.