International photographer (Jan-Dec 1934)

Twelve The INTERNATIONAL PHOTOGRAPHER July, 1934 A NEW ERA FOR THE AMATEUR DEVELOPMENT AND PROCESSING OF SMALL CAMERA FILMS 1,00 feet unit used at Davidge Film Laboratories A new era for the amateur development and processing of small camera films is ushered in by the advent on the market of the Hollywood Roto-Tank. The unit is a small edition of the developing system which the Roy Davidge Laboratories are using for commercial work. Roy Davidge, for some years past, has catered to the individual processing of negatives, daily prints and dupes, giving special attention and development to suit the particular tastes of cameramen and producers. This type of work presented a problem difficult to cope with on the conventional type of developing machines. Three methods of sound recording requiring five different sensitometric standards on four brands of film added complications. The rack and tank method of development was a fairly simple answer to the situation, but it had three major drawbacks: rack flashes, the inability to handle rolls larger than 400 feet and the lack of necessary agitation of the solutions used on the faster emulsions that were being developed by the raw stock manufacturers. With the aforementioned requirements in view, the Davidge Laboratories evolved a system of unit development which has all the flexibility of the rack and tank system with none of its drawbacks. Each of the new developing units has a capacity of approximately 1100 feet and consist primarily of a wheel or rotar having alternating vanes to agitate or direct the developing solution to the surface of the film at opposed angles. A celluloid separator with staggered, elongated protuberances breaks up the cross currents from the agitators and displaces the solution on the emulsion surface of the film approximately 480 times a minute with a constant change of current direction. The tanks in which the unit operates use a floor space 1 x 4 feet each and contain approximately 47 gallons of developer, different formulae to meet individual needs can be handled by no great cost by either materials or floor space. The principal advantages, from the producer's angle, are a better quality negative and positive due to greater color gradations through all densities from flesh tones to shadows. Better duping prints and negatives can be produced by films processed by this method, owing to a smaller grain structure being obtained by the use of weaker solutions, depending on extreme agitation to produce the required densities. The smaller units in all essentials duplicate the results obtained with commercial equipment. The RotoTank can be loaded in a change bag or dark room and all other operations carried on in the light. The film capacity is 25 feet of 35 mm. or 50 feet of 16 mm., eighteen (18) fluid ounces of liquid are used in each operation. A unit is highly adaptable to the needs of cinematographers and sound units when on location. The test strips produced in the Roto-Tank will duplicate the best results obtainable at the studio laboratory. THE RETURN OF THE ARC Recent developments in motion picture photography have shown a definite trend toward the return of the arc light. The quality of photography obtainable with the arc light, — which closely approximates the quality of sunlight,— has never been questioned ; but other factors such as the noise from the mechanism, the hum of the generator and the cost of manpower to operate the searchlight types caused them to be displaced to a very large extent. Gradually the searchlight and spotlights of the carbon arc type have found their way back into general usage. Improvements have been made by the studios themselves which take care of the objectionable electrical and mechanical features. The additional manpower required to operate arc lights of the searchlight type is more than justified by the results obtained. This is proven by the fact that almost all of the searchlight type lamps are again in use. This trend on the part of the studios has given the manufacturers of carbons and carbon lamps the courage to go ahead with a program of development. Recently a new type high intensity studio carbon was announced. In order to meet a demand for a silent and efficient flood lighting unit the Mole-Richardson Company built a general flood light, of the side arc type, around this new carbon. While the new carbon is only eight millimeters in diameter and the new floodlamp weighs a great deal less than the old type, they were able to increase the intensity of illumination from approximately sixty-five foot candles at fifteen feet with the old type lamp to a figure which exceeds two hundred foot candles with the new unit. In both cases the same wattage was used. These lamps have given excellent service on a number of Technicolor pictures and are now finding their way into black and white photography. From a standpoint of efficiency, silence and light quality, this new type lamp seems to be an ideal unit wherever general floodlighting is required. There is no reason why this new development in carbons should not be used in the spotlight and searchlight type lamps also and considerable work is being done to provide a light and efficient spotlight and sun arc. It is quite probable that the near future will find the perfection of light weight semi-automatic lamps, of the eighty ampere rotary spot and sun arc types. LIEUT. FELSTEAD IS SOLDIERING Lieutenant Charles Felstead, Associate Editor of the International Photographer, has been assigned to active duty with the 63rd Coast Artillery (AA), at Fort McArthur. The regiment left recently on its annual man euvers that are taking it through the more northern part of California, where tactical and anti-aircraft defense problems are being worked out under actual field conditions. Please mention The International Photographer when corresponding with advertisers.