There are two Problems in color temperature, one is the concept of it, and another is the technique of its measurement. The former is discussed in this report, and the latter will be discussed in the next report. In early days, the concept of color temperature was used to indicate the color of light source in visual photometry, but now applied also in color photography.
Because visual color temperature is defined as a temperature of black body radiation having minimum color difference to the chromaticity of the source in question, color temperature is varied with an uniform chromaticity system which gives the metrics of color difference.
When a illuminating source of non grey body such as daylight, carbon arc and fluorescent lamp is used in color photography, visual color temperature can not describe necessarily photographic effect. Therefore, a photographic color tenperature based on color sensitivities of film must be defined in color photography. The author adopted the mean sensitivities of various films for a standard sensitivity, and reviewed methods to indicate photographic color temperature.

View full abstract

The volume of nitrogen produced by iodine-azide reaction of filtered and unfiltered gelatins were measured with a simple instrument deviced by one of authors. The filter papers used in the experiments were No.Sc and No.85 of Toyo Filter Paper Co. Ltd. and gelatins were commercial ones.
As the filtered gelatins always showed values smaller than the unfiltered ones, it is concluded that main substances which react iodine-azide reagent were minute solid matters contained as impurities in gelatins.
Values of Vogel's reaction and physical retardance were also compared between the filtered and the unfiltered, Physical retardance of filtered gelatins were also smaller than that of the unfiltered.

View full abstract

It is well-known that the colour balance of colour film depends upon the colour temperature of illumination.
Since no qualitative study was given in literature on the reproducibilities of colours when exposed directly to light sources of various colour temperatures, we submit here studies of reproducibilities of colours of light of incandescent tungsten lamp of high and low temperature. It is especially carried out for the purpose of measuring the temperatures of furnaces, explosions and so on.
Of various factors which can affect on the colour balance, quality of light and amount of exposure were sudied on 6 kinds of films both negative and positive included.
The light source is gas-filled monoplane coiled tungsten filament lamp burned at 2848°K, 2000°K and 1500°K. DG-filters were used also in order to cenvert 2848°K to 6500°K and 4800°K. Exposures were carried out frame by frame on 5 meter optical bench using NSG sensitometer penbulum as a shutter (1/20 sec.) vering distance between lamp and films mounted in 35mm camera body in order to obtain stepwise reduecd illumination.
Spectral transmittancies of the developed films were measured by GE automatic recording spectral photometer, as an example Fig.1 is shown, and trichromatic coodinates were calculated (Table 1) and plotted on colour diagrams (Fig. 2 and 4). Discussions were made on curves connecting these poins. Relations between colour temperatnre and ratios of two wave length densities coresponding red and green are shown in Fig. 5 and changes of dominant wave length vs. colour temperature are also shown in Fig. 3. characteristic curves (HD curves) were shown in Fig. 6, and figures of relative sensibilities and gamma are given in Table 3.
In conclusion it is difficult to determine temperatura from its trichromatic coodinates on the colour diagram, but with some treatment of spectral transmittancies of developed films temperature determination can be done.

View full abstract

On the mechanism of latent image formation by ultrasonics in water, effects of thickness of protecting layer of gelatin were investigated. It was observed that the softening of protecting layer was an important factor in the formation of the latent image.
Pressure of cavitation was estimated from data of experiment and through calculation. The estimated pressure distribution was compared with the distribution of the latent image which was obtained by electron micrographic observation.
From the above experimental results, it was assured that the mechanical effect of cavitation is always concerned on the latent image formation by ultrasonics in water.

View full abstract