American cinematographer (Jan-Dec 1926)

Twenty-four AMERICAN CINE M AT O GR APHER June. 1926 Cameras Qo Ouer the Top Three cameras in tandem, so to speak, were used by E. B. Du Par, A. S. •'.. during the filming of the night battle scenes showing a section of the German and English front line trenches for the Warner Bros, production of "The Better 'Ole." starring Syd Chaplin and directed by Charles "Chuck" Reisner. on the Vitagraph lot in Hollywood. These cameras were mounted at intervals of about ten feet on the three stories of a forty foot parallel. Director Charles "Chuck" Reisner was on the top level equipped with a telephone connected with a Western Electric Public Address System of a dozen units scattered at strategic points over the five acres of trenches, barbed wire, and mud. Thirty sun-arcs, forty side arcs, and ten rotaryspots furnished the illumination. These were grouped around the field, four of the most powerful being placed on fifty and seventy-five foot parallels on either side of the camera. This equipment was powered by four gas and one power generator. Four wind machines kept the field reasonably free of smoke from the explosions. tendency to form a precipitate with hydroquinone in alkaline solutions limits the concentration that can be added to a strong hydroquinone developer, but with ordinary elon-hydroquinone or pyro developers it can be used satisfactorily. Pinakryptol green is much more expensive than phenosafranine at the present time. Its composition has not been published although the general structure of the class of dyes to which it probably belongs was recently described by Homolka.,J 4. Pinakryptol Yellow. Pinakryptol yellow desensitizes more powerfully than pinakryptol green in the same concentration, and can be used much stronger because of its colorless, non-staining solution. Also it is much more active in destroying the color sensitivity of a panchromatic emulsion. When tested with Eastman Commercial panchromatic film and an elonhydroquinone tank developer it was found to have no effect on the latent image or its subsequent development. It cannot be added to a developer, however, as it is destroyed by sulphite, and some other desensitizer must be used in the developer to prevent the film from regaining its sensitivity during development. A solution of pinakryptol yellow is also said to be slowly decomposed by exposure to light.'". It differs from other common desensitizers in that it greatly retards the direct photochemical blackening of an emulsion such as developing paper. As a preliminary bath for desensitizing panchromatic film, it is the most effective of all the desensitizers considered in this investigation. 5. Pinakryptol. Pinakryptol which was on the market before pinakryptol green, consists, according to Luppo-Cramer,1 4 of a mixture of pinakryptol yellow and pinakryptol green. 6. Basic Scarlet N. Basic scarlet N was proposed as an effective desensitizer by the Laboratory of Pathe Cinema .15 It is apparently a mixture of safranine and auramine.1'1 Hubl17 states that it is less effective in desensitizing panchromatic emulsions than pinakryptol green and that its desensitizing power in a developer is no greater than in water solution. Tests in this laboratory have shown that it offers no advantage over phenosafranine in desensitizing 11. Stammreich and Thuring, Zeit Wiss. Phot. 2K, 363, ( 11)25). 12. B. Honiolka, "New Desensitizing Dyes,'' Phot. Ind.. 1925, p. 347. 13. A. Hubl, "Contribution to the "Knowledge of Desensitizers." Phot. Rund. 62, 71. (1925). 1-1. Luppo-Cramer,. "The Origin o( Pinakryptol Green and Other Dyes." Phot. Ind. 1924, p. 1l!i4. 15. Research Laboratory of Pathe Cinema. "New Desensitizers," Le Phot 11, 296, 1924. 16. Lumiere and Seyewetz, "Constitution of Desensitizing A/.ine Dyes." B. .1 Phot. 72. 446, (1925). 17. A. Hubl, "Basic Scarlet X as a Desensitizer," Phot. Ind.. 1025, p. 4.X2.