The Optical Magic Lantern Journal (June 1890)

4 The Lantern Society. THE session proper of this society is to commence about the end of September. Although the committee have under consideration several propositions respecting the most central and convenient premises, yet up to the present date no definite decision has been made regarding the rooms or hall to be engaged ; but asthe committee meet on June rith, doubtless the locality will then be decided upon. The council have suggested that the objects of this society may be best attained : — (1) By the engaging of premises in some central position in London, at which the meetings of the council and of the society may be held; (2) by acquiring suitable apparatus for the purpose of giving exhibitions of general and scientific interest to both members and their friends ; (3) by obtaining the services of specialists in every branch of art or science suited to optical demonstration ; (4) by offering—as far as the funds of the society will permit—remuneration or awards for the development of the optical lantern, and all apparatus pertaining thereto; (5) by imparting instruction to those who are desirous of learning how to effectively manipulate the optical lantern, to produce slides and apparatus, and to efficiently employ the same both in private and public; (6) by securing for the members of the society special and advantageous terms from manufacturers and others for the purchase or loan of apparatus and slides ; (7) by forming a large and comprehensive loan collection of lantern transparencies pertaining in art, science, and kindred subjects; such loan collection to be placed at the disposal of every member upon conditions to be laid down by the council; (8) by providing a means of inter-communication between the members of the society, whereby each member may be made acquainted with the private collections of his fellowmembers, and may be able to negotiate a mutual loan if so desired ; (9) by arranging an interchange of demonstrations between photographic. microscopical, and other societies interested in optical lantern work. Already about forty members have been enrolled, and we would suggest that those desirous of joining should consult the hon. sec., Lieut. C. E. Gladstone, R.N.. 6, Bolton-street, Piccadilly, W. Lantern Slide Work.* THERE is no better or more pleasing way of showing photographs than by exhibiting them on a screen by the aid of the optical lantern ; the fact that so many people go to our lantern exhibitions is in itself a proof that this branch of photographic work is appreciated, and to the photographer the artistic qualities and fuilings of his work become more manifest when seen enlarged on the screen than, when viewed on a small print. It may be well to allude to the best size of camera to work with, as some amateurs do not care to make anything but lantern slides. Small cameras are made to take a plate 3} square, and although this may do for ordinary landscape work, it is practically useless for instantaneous photography, such as marine and seaside studies, cattle pieces and other moving objects. * Leeds Photographic Society. Many who work }-plate cameras have found them too small for this class of work, and have been considerably disappointed when the plate has been developed to find nothing but a barren waste of water, or a field with the surrounding fence as the only subject on the plate. I would, therefore, advise nothing less than j-plate, or 5 by 4. J_antern slides are made either by ‘direct contact,’ or by “reduction” from the negative by re-photographing from the negative. Slide making by “direct contact” is the plan most generally adopted by amateurs, because of the ease with which it can be done by artificial light ; but I very much prefer, however, making slides by ‘‘ reduction,” especially if working from a }-plate or larger negative. No doubt very good slides are made from $-plate negatives by “ contact,” but how few pleasing ones are made from the larger sized negatives in this way, for when taking a view with the camera, you study the proportions and composition of the picture in relation to the size of the plate you are working, and not simply with the idea of printing out a picture 34 square ; it is only by “ reduction “ you can get the full value of your negative on the lantern plate. Another advantage obtained by “reducing " is that a soft slide may be made from a hard negative, and also good slides from poor and faulty negatives, negatives from which it would be impossible to make a slide by ““ contact,” or even to get a passable silver print from. In “ contact” printing the length of exposure required of course varies according to the make of plate used, and the density of the negative. I think it is best to have one fixed distance from the light for exposing the slide, and to vary the time of exposure according to the density of the negative, rather than vary the distance. If the distance the frame is held from the light be varied, always remember that the length of exposure will increase as the squares of the distances the frame is held from the illuminant, and notin a numerical ratio; for example, if an exposure of ten seconds at the foot distance is sufficient, and the distance is increased to 3ft.,an exposure of 90 seconds will be needful. For making slides by ‘ reduction” some sort of reducing frame is required to hold the camera and negative. The apparatus is, however, very simple. It consists of a base board, on which there is a sliding block to carry the camera at one end, and at the opposite end a deep box about roin. or 12in. square, open at the end next the camera, the other end holding a sliding carrier in which to place the negative. “ Reductions” are best made by daylight. The plan I adopt is as follows : Having placed my reducing frame, on which I have fixed a }-plate camera, in front of an upper window (in the lower square of which I have inserted a sheet of ground glass for the purpose of diffusing the light), I place the negative in the sliding carrier and carefully focus it; then stop down the lenses to U.S. 16, and expose the plate in the usual way. The exposure, of course, varies according to the light and density of the negative as in “contact” printing. A long exposure and retarded development will give warm tones; a short exposure and active development will give black tones, and I find the tones are always warmer if the exposures are made ona bright sunny day than even with a long exposure on a dull day. I advise, however, that workers should