English Translation

2-305 To special installation III to K 15 — 101 — 52. Contact copies = copies in original size of the negative. Only formats 9×12 produce effective images. For this purpose gas light, chlorine brom silver paper (contact papers, e.g. Agfa Lupex). In the copy frame or in the copy machine, the layer of the plate is placed against the paper layer and exposed through the negative onto the light sensitive paper. How long to be exposed depends on the density of the negative, the intensity of the illumination (light source) and the sensitivity of the paper. Small negatives (small film negatives) must be examined. The magnifying devices serve this purpose: 3 types are distinguished with regard to the lighting device: 1. Apparatus for indirect reflex light; these work very soft, therefore require strongly covered negatives; 2. Condensor apparatus for direct light; they work very hard and rich in contrast. 3. Condenser apparatus with opal lamp (Leitz, Focomat). Eukobrom (1 : 1) is also a highly recommended developer, who gives deep black pure shadows. For each negative, the paper (grade of hardness) best suited to its character must be used. See Table II. In this way, it is possible to make a good copy or magnification of each semi-usable negative. In orange or yellow darkroom light, the copies look darker, so the development must not be interrupted too early. Extortion of the images in the developer creates flaue, powerless, yellowish colored photos. The pictures are fixed for 10 minutes, approx. 1⁄2 hour watered and brought to high gloss in the high-gloss electric dry press. It is important to keep the high gloss foil clean, which can be rubbed with alcohol from time to time. The papers are to be moved continuously in the baths, otherwise stains can be created. Table III. 1. The paper gradations required for negative different characters: coverage of negative gradation of negatives thinly normal densely required paper stratification hard unusable soft to extra soft soft to Extra soft and long exposure normal to hard normal normal and long exposures soft hard to extra hard hard hard to ultra hard hard and long exposed flau extra to ultra-hard hard to Extra hard hard tough to extra-hard and long-exposed 2.Diapositive: Instead of the paper supervision images, you can also produce transparent slides on glass or celluloid basis. Today almost only the slide format 5×5 is used. It is not possible to copy the negative directly (in contact printing) on slide plates 5× 5 or slide film 24×36 mm, or to use the negative from below (light box) and the small reproduction apparatus for the contax (setting 1 : 1). The slide film is in this case in the Contax. If the slide positives are to be generated on 5X5 plates, the slide plate adapter is used. Zeiss-lkon produces corresponding auxiliary devices to the Contax and Leitz to the Leica. Plate dias should be clearer and more brilliant than film diapositives. The development is best done in Eucobrom. Of larger plates 9×12 etc., also Verkl ein erung en on Dias 55 can be made. (Light box.) Image throw by 35mm slide projector of Leitz or Zeiss-Ikon best on pearl wall, which results in very bright plastic images. For smaller rooms, in which to project, projectors with shorter focal length, e.g. 8.5 cm, are recommended. With longer focal length the necessary distance projector screen can be too large, i.e. The length of the room no longer be sufficient. Unnecessary to cover slide by adhesive strips! Pay attention to the most embarrassing cleanliness, dirt particles appear hugely enlarged on a screen. Slides with a layer turned to the apparatus and insert head-standing into the sliding frame of the projector gate. Projector lamps 250 watts. Color films do not project too long, as they may be. L can take damage. L