Home Movies (1943)

HOME MOVIES FOR JANUARY o Blue photofloods are manufactured only for one purpose — to supplement daylight. Here, blue photofloods are employed as booster lights in an exterior scene otherwise illuminated by daylight. Color filming, with bue PHOTOFLOODS B y M it RECENT queries to the editors suggest that some amateurs are confused or at least are not fully informed regarding the values and limitations of blue "daylight" photofloor lamps, especially when used with Kodachrome. A recent question concerned the probability of using blue photofloods as a means of illuminating interiors that were to be filmed entirely with regular outdoor Kodachrome. It is erroneously believed by some that the illumination supplied by blue photofloods approximates that of daylight both in intensity and in color and, therefore, it would be possible to successfully use these lamps in lighting interior sets to be filmed with regular Kodachrome. This is not only untrue but the light emitted by blue photofloods is of lesser intensity than that of regular photofloods due to the blue color of the glass from which the globe is made. In Kodachrome photography, not only are the direction and intensity of the lighting important, but also color of the light. Ignorance of this fact probably accounts for much of the unsatis factory results which have been had by many serious amateurs using color film. Long before Kodachrome was introduced, photofloods had become the established means of illumination for indoor photography where artificial light was used. When the type A Kodachrome emulsion for interior use was evolved, it was based upon a standardized color temperature of the original white photoflood bulb. The color temperature of these photofloods is still much lower than natural daylight even though it is higher than that of the average household mazda lamp. And in spite of its visual brilliance, the standard photoflood emits less blue and green light as compared to its emission of red and yellow. Daylight or "regular type" Kodachrome, therefore, if used indoors with regular photofloods, would produce pictures preponderantly reddish in tone. Thus we have in the regular photoflood a lamp which is not only lower in color temperature than natural daylight, but deficient in its ability to emit adequate blue and green light for regular Kodachrome photography. The blue "daylight" photoflood, on the other hand, while possessing an inherent ability to correct the color of light, is likewise short of actual daylight in color temperature, being rated at 4000" K when burned at 120 volts as compared to the color temperature of daylight of approximately 6000" K. for which regular Kodachrome is balanced. Blue photofloods are manufactured only for one purpose — to supplement daylight. If an interior must be filmed which requires artificial light but where some natural daylight is coming through a window within the field of the camera lens or even outside the camera range, blue photofloods are required to balance the illumination for color for daylight Kodachrome. These lamps are recommended for no other use. It is uneconomical to use the more expensive blue photofloods with daylight Kodachrome as the sole source of illumination. The color values are not as critically held to an absolute color temperature as is the case with regular photofloods. This is a practical difficulty arising out of the fact that it is not feasible to make lamp bulbs of tinted glass with the same accuracy as filters are constructed. In using either white or blue photofloods, it is important to maintain the correct voltage for which the lamps are made to burn. This at once presents a difficulty for the average amateur shooting pictures in the home, for certainly few, if any, have the means at the.r command to regulate the voltage in the power line entering the average dwelling. This statement is offered, however, to indicate one of the difficulties that lies before the amateur seeking the pinnacle of perfection in indoor Kodachrome photography. In studios, it is possible to regulate current voltage, to increase or decrease it according to number of lights being used, in order to obtain the maximum efficiency from incandescent lights. With the electrical load required in lighting the average amateur indoor setting, some drop in voltage is certain to result. And if shooting takes place in the early evening hours, the voltage will be even lower. In professional studios, if the voltage is low and cannot be raised, color temperature is compenpensated for through use of filters, al • Continued on Page 26 16