The international photographer (Jan-Dec 1935)

Eighteen The INTERNATIONAL PHOTOGRAPHER April, 1935 \ MINIATURE CAMERA PHOTOGRAPHY Flying high. Photo by A. Wolfman. Agfa Superpan Film; Leitz No. 1 filter. Developed in p-diamine — glycin. \U FAY COLOR: The manner in which color photography is progressing lately points to the fact that it may become quite popular in the near future. The latest process available to the miniature camera enthusiast is Dufaycolor, which is at present supplied in the 35 mm. film size. It is a three-color regular mosaic screen process, the mosaic screen being printed upon the base of the film in a unique manner— in the form of fine color lines microscopic in size, about 40 lines to the millimeter upon a layer of collodion of one color. As in the usual manner with such processes the film is loaded into the camera with the base side toward the lens, so that the light passes through the mosaic color screen before it reaches the emulsion. The film is processed by the reversal method, the original film becoming the positive used for projection. Laboratories are already offering processing service for Dufaycolor. The speed of the film is between 17° to 19° Scheiner allowing considerable latitude in the manner of subjects that can be photographed. From the samples I have witnessed, by projection, it appears that the future of Dufaycolor is quite promising. News of the Rolleicord and Rolleiflex: Burleigh Brooks informs us that the 6x6 cm. Rolleiflex will now be equipped with a Zeiss Tessar f :3.5 lens instead of the f:3.8, and will have the new high speed Compur shutter with speeds up to 1 /500th part of a second. The smaller 4x4 cm. size will also have the new high speed shutter on the model with an f :2.8 lens. A new model of the Rolleicord will be supplied with an improved and more beautiful real leather cover, and with an f :3.8 lens. The former model is equipped with an f :4.5 lens. New Derby Enlarger: Another announcement from Burleigh Brooks mentions a new Derby enlarger for negatives 4x4 cm. and smaller, capable of yielding enlargements up to 40 times, and greater The focusing knob on the lens collar is adjustable to three positions, permitting the lens to be used closer to the negative, thereby allowing such great enlargements. It is also equipped with double condensers, and an all-metal negative holder easily adjustable to four size openings, for 24x36 mm., single cine frame, 3x4 cm., and 4x4 cm. negatives. Other features are also included. Paraphenylene-Diamine Hydrochloride: In the January issue this new developing agent was described, and formulas suggested by its distributors were listed. I presume that many photographers have already experimented with it, having arrived at definite conclusions regarding its advantages, or disadvantages, and have possibly devised new formulas with which to obtain successful results with it. We would like to hear from such photographers telling of their results, and the formulas which they are using so that this information can be passed along for the benefit of other miniature camera users. /2 gram 37.5 grams 500 c.c. 36 min. 30 min chromatic and orthochromatic films with good results. If supersensitive panchromatic films are used an additional gram of glycin, and of P.D.H. can be added: P.D.H. -------- 5 grams Glycin ------- 5 grams Metol ------- Sodium sulphite (anhydrous) Water, to make Developing Time 60°F. (16°C.) ----65°F. (18°C.) ----70°F. (21°C.) ---- 25 min. Metol in Paraphenylene-Diamine Formulas: Photographers who have been using p-diamine have no doubt noticed the tendency of this agent to readily attack the highlights, developing them to such an extent that at times they appear over-exposed, and not developing the shadows so as to properly bring out the detail in them. For this reason many workers are now incorporating metol in the p-diamine — as the inclusion of metol in the above P.D.H. — glycin formula. Metol has opposite qualities to that of p-diamine. It brings out the detail in the shadows which otherwise would be lost, and its use in conjunction with p-diamine does not entail sacrifice of too much fineness of grain. A Tip on Print Flattening: This process can be performed in a little quicker time with good results if the backs of the prints are moistened with a 70 per cent solution of alcohol (ordinary rubbing alcohol obtainable at any drug store) before being pressed, instead of water. The alcohol can be applied a little more freely than water for it evaporates quickly. It is best to wait until the prints are bone dry before applying the alcohol ; they can be dried in quick time if all surplus water is blotted off them when they are removed from the wash water to be set aside to dry. More on Individual Development : Last month a brief discussion was included on the individual treatment of miniature negatives, according to the subject photographed. Perhaps it would simplify matters if a few different types of subjects were mentioned and the change in the developing time necessary to render them properly. These alterations of the developing time are approximate, being intended as a guide for the miniature worker in developing his negatives. Landscapes and architectural subjects can be developed from about 20 to 40 per cent greater than the normal time, and portraits should be developed for one-third to about one-half less, according to the type of lighting and film employed. Subjects taken on dull days, or in flat CINEX TESTING MACHINES CINEX POLISHING MACHINES BARSAM-TOLLAR MECHANICAL WKS. 7239 Santa Monica Blvd. Phone GRanite 9707 Hollywood, California The following formula has been used for regular panPlease mention The International Photographer when corresponding with advertisers.