Amateur Photographer & Cinematographer (1935)

December 4th, 1935 The AMATEUR PHOTOGRAPHER a 6 CINEMATOGRAPHER a was stated by the demonstrator, Mr. E. R. Davies, to be the only practical subtractive process in which one and the same film both effects the colour separation in the camera and produces, after passing through a suitable reversal process, a colour print for projection. Three super¬ imposed emulsion layers sensitive to the primary colours cause the colour separation to be made auto¬ matically during exposures. These are afterwards converted into three dye layers of the complementary colours which, being superimposed, give the desired colour print. The difficulty is in the processing, but the amateur cinematographer does not take a hand in processing in general. The processing was ela¬ borately explained, however — four developments followed by four bleaching baths, involving the carry¬ ing out of quantitative chemical reactions in sharply restricted layers of gelatine film which itself has a total thickness of less than onethousandth of an inch. But from the point of view of the user, he can handle Kodachrome as he would handle ordinary cine film, taking colour photographs in a cine camera without recourse to high -aperture lenses. Artificial-light photography presents no particular difficulty except that a compensating filter should be used to reduce the high proportion of red light present in artificial illuminants. “ Most people will agree,” said the chairman, after the two reels had been pro¬ jected, “ that we have never seen pictures like these before — pictures, too, produced in a comparatively easy way by the amateur, though not so easy for the processer, and still less easy for the people who have had to put up the tremendous apparatus and go through the neces¬ sary research. But we are getting nearer to perfection every time,, and this is the nearest I have seen.” Photography cannot lie. It was interesting to hear of a famous golf professional who has been careful to teach all his pupils not to twist the wrist. Recently he went to see the first cine picture taken of him in action on the links, and lie discovered that he himself was doing that very thing ! The A mateur Photographer” EXPOSURE T ABLE — December EVERY MONTH a brief exposure table will be provided for the assistance of our readers in their practical work. A glance at the current approximate exposures as here given will serve as a reliable guide for most purposes. The subjects will be varied to suit the time of year. The following exposures will serve as a working guide for any fine day during the month, between the hours of 10 in the morning and 2 in the afternoon, with the sun shining, but not necessarily on the subject. Stop used, f/8. The exposure should be doubled if the sun is obscured or if stop f/11 is used. For f/16 give four times the exposure. For f/5.6 give half. From 8 to 10 a.m. or from 2 to 4 p.m., double these exposures. From 7 to 8 a.m. or from 4 to 5 p.m., treble them. Subject. Ordinary. Medium. Rapid. 1 Extra Rapid. Ultra Rapid. Open seascapes and cloud studies . . 1/20 sec. 1/30 sec. 1/60 sec. 1/80 sec. 1/100 sec. Open landscapes with no very heavy shadows in foreground, shipping studies or seascapes with rocks, beach scenes . . 1/10 y y 1/15 y y 1/30 y y 1/40 y y 1/50 y y Ordinary landscapes with not too much foliage, open river scenery, figure studies in the open, light buildings, wet street scenes 1/4 y y 1/6 y y 1/12 y y 1/15 y y 1/20 y y Landscapes in fog or mist, or with strong foreground, well-lighted street scenes . . 1/3 y y 1/4 y y 1/10 y y 1/12 y y 1/15 y y Buildings or trees occupying greater portion of pictures, river scenes with heavy foliage 3/4 y y 1/2 y y 1/4 y y 1/5 y y 1/6 yy Portraits or groups taken out of doors, not too much shut in by buildings . . 2 secs. n y y 1 y y 1/2 y y 1/3 y y Portraits in well-lighted room, light sur¬ roundings, big window, white reflector . . 6 y y 5 secs. 3 secs. 2 secs. \\ yy Asa further guide we append a list of some of the best-known makes of plates and films on the market. They have been divided into groups, which approximately indicate the speeds referred to above. The hypersensitive panchromatic plates and films require less exposure than the ultra-rapid. Ultra Rapid. Agfa, Special Portrait. „ Isopan ISS Film. „ Super-speed Film „ Isochrom Film. „ Ultra Special. Barnet, Press and Super Press. „ XL Super-speed Ortho. „ Soft Panchromatic. „ Studio Fast. „ Ultra Rapid. Eastman, Par Speed Cut Film. „ S.S. Cut Film. „ S.S. Pan. Film. Gevaert, Super Sensima. „ Sensima Fast. „ Sensima Ortho. „ Super Chromosa. ,, Roll Films and Packs. Ilford, Golden Iso-Zenith. „ Iso-Zenith. „ Hypersensitive Pan. Plates and Films. „ Portrait Film (Ortho Fast). „ Monarch. „ Press. ,, S.S. Ex. Sens. „ Zenith Ex. Sens. „ S.G. Pan. Illingworth, Fleet. „ Super Fleet. ,, Super Fleet Ortho. „ Pan. Fleet. Imperial, S.S.S. Press Ortho. ,, Eclipse. ,, Eclipse Ortho Soft. „ Eclipse Soft. „ Eclipse Ortho. Imperial, Eclipse Pan. Soft. Kodak, Verichrome Film. Marion, Record. „ Iso Record. Selo, Selochrome Roll Film and Film Pack. „ Selo. Pan. Roll Film. Voigtlander, Illustra Film. Wellington, Anti-screen. ,, X Press. Zeiss Ikon, Pemox Roll Film and Packs. Extra Rapid. Agfa, Chromo. „ Isolar. Extra Rapid. Isolar. Iso Rapid. „ ,, Chromo. Roll Film. Barnet, S.R. Pan. „ Studio Ortho. Ensign, Roll Film. Gevaert, Filtered Ortho. „ Chromosa. „ S.R. ,, Regular Cut Film. Ilford, Auto. Filter. „ S.R. Pan. „ Pan. Film. „ Rapid Chromatic. Imperial, Non-filter (new series). „ Eclipse Pan. B. ,, S.S. Ortho. Kodak, Roll Film and Film Pack. Pathe, Roll Film. Selo, Roll Film. Zeiss Ikon, Roll Film and Film Pack. Rapid. Barnet, S.R. „ Self-screen Ortho. Ilford, Screen Chromatic. „ S.R. ,, Commercial Ortho Film. Imperial, Non-Filter. S R ,, S.R. Ortho. Kodak, Cut Film. Medium. Ilford, Empress. „ Chromatic. Ordinary Barnet, Ordinary. Gevaert, Ordinary. Ilford, Ordinary. „ Rapid Process Pan. Imperial, Ordinary. „ Pan. Process. 528 8