Amateur Photographer & Cinematographer (1933)

Ih[ amateur photographer p 6 CINEMATOGRAPHER a August gth, 1933 ‘Deciders' Questions ANSWERED General. — All communications tor the Editor should be addressed : “ The Editor, The Amateur Photograhhe» atid Cinematographer, Dorset House, Stamford Street, London, S.E.i,” and in every case, without exception, must pive the name and address of the writer. Contributions. — The Editor is glad to consider original, up-to-date manuscripts on photographic subjects. All contributions must be typewritten, or in very legible handwriting on one side of the paper only Letters or communications arising out of matters already appearing in the paper — ^ .101 paid tor. The Editor disclaims legal responsibility for the safety of matter submitted to him, but he will endeavour to return rejected manuscripts, etc., when a stamped addressed envelope is enclosed. MSS. or prints that are not actually accompanied by a stamped wrapper or envelope can in no case be returned. Reproduction fees for prints are only paid by arrange¬ ment beforehand. The sending of a print, without any condition stated, will be taken as permission to reproduce it without fee. Enquiries and Criticism. — Advice, Criticism and Information are freely given, but the following conditions should be read carefully before applying, as any communication which does not comply with the rules must be ignored . (1) See " General ” above. (2) Every question and every print for criticism must be sent separately through the post, and must be accompanied by a separate stamped addressed envelope. No exception can be made in any case to this rule, except so far as enquiries or prints from Overseas are concerned. (3) Neither enquiries nor prints for criticism must be enclosed with competition prints. (4) On the back of each print sent for criticism, in addition to the name and address of the sender, must be the title (if any), and the criticism coupon from the current issue. (5) Enquiries should be clearly written, on one side of the paper only, and should be specific and not general. Such enquiries as “ How can I take interiors ? ” or “ Can you give me some hints on outdoor portraiture ? ” are too general to be dealt with in this section. (6) All envelopes should be distinctly marked “ Query ” or “ Criticism," as the case may be. (7) Prints are sent for advice or criticism on the distinct understanding that by so doing per¬ mission is given for their reproduction without fee. We endeavour to deal promptly with enquiries, but cannot undertake to answer by return of post, nor can we give precedence to any enquiry. A selection of those replies is printed each week, but all questions are answered by post. Enquiries from abroad must contain a coupon also, but it need not be from the current number, and should be cut from the latest issue to reach the enquirer. Spots on Negatives. What is the cause of the " pin-points ” on my negatives (sample enclosed) ? I give particulars of development, etc. K. W. S. (Colwyn Bay.) There is every indication that the spots on your negatives are due to dust, and, as there is nothing of the kind on plates as sold, it is evident that you are getting dust on your plates at some period before actual exposure. You give particulars as to your developer and fixing, which have nothing to do with the case, but you say nothing about the dark slides or anything of the kind. It is possible that your camera may be dusty inside, or that there is dust in the dark slides or plate-holders themselves. Dust even on the outside of slides will cause the trouble, as when the safety shutter is drawn the dust is dislodged, flies about, and settles on the plate. Green Tones. Can you give me a formula for green tones on bromide paper ? J. R. S. (Hull.) Although it is possible to obtain green tones on bromide paper the method is a somewhat complicated one, and cannot be adequately dealt with in the form of a reply ; it is one of those things upon which it is necessary to consult a reliable textbook. In our own case we should prefer to obtain from the bromide print a print in green pigment by the Carbro process. There is then a choice of colours, and the results are more reliable and satisfactory. Dish Development. Has the old-fashioned method of dish development any* practical advantages, or is it upheld by some only for sentimental reasons ? E. F. (Manchester.) Those who advocate dish develop¬ ment do so, not for sentimental reasons, but because it gives them facilities for observation which, to experienced workers, are often of the greatest value. Hand Camera Exposures. I have had long experience with a field camera, but none with a hand camera. Can street scenes and buildings be taken without a stand ? If so, what exposure and aperture ? R. A. C. (Goodmayes.) It is quite impossible to tell you what exposures to give with a hand camera. From the experience you have had you would certainly not ask us what ex¬ posures you should give with a stand camera, yet it is obvious that the exposure is not dependent upon the type of camera used. Of course, street subjects can be taken with a hand camera, and in many cases better than with a stand camera, but the question as to what exposures to give in all circumstances is one that cannot be answered. One factor is the movement of people and vehicles, another is the light, and another the character and lighting of the subject. See what you can do with 1 /25th of a second at f/8. Oil Reinforcement. In his description of his exhibition work Mr. A. E. Marden mentions that all his prints are finished by the oil-reinforcement method. Would you give me particulars of this method, formulae, etc. ? H. W. M. (Wembley.) Working-up prints with oil pigment is not a matter that can be dealt with in the form of a brief reply to a question. It is quite probable that you will find the necessary information in one of the Beginner’s lessons before very long. Fogged Negatives. What is causing the margin fog on my negatives ? J. A. (London.) There is nothing about your negatives that you need worry over. With some films and developers it is difficult, if not impossible, to avoid slight general fog¬ ging. Where this is both slight and even, as in your case, it can safely be ignored, as it has no effect beyond very slightly increasing the exposure. Camera Instructions. I have been given a camera which is much more complicated than the only other one I have ever had. Where can I get instructions that will explain all about it ? J. S. (Grimsby.) Probably the makers issued a book of instructions with the camera, but you give no information as to make or type. Most of the information you need will be obtained from a textbook dealing with hand cameras. We think your best plan, however, will be to hunt round for an experienced friend, who can explain and demonstrate the various parts and movements. Fixing Varnish. Will you give me a formula for a fixing varnish to spray on to crayon coloured prints ? W. W. A. F. (Weston-super-Mare.) We doubt whether you can make any varnish as good as those on the market, but the following is a method of pre¬ paring one : In a wide-mouthed bottle put 2 oz. of best white shellac, and pour over it 14 oz. of methylated spirit. Cork it up and leave for a day or two, giving an occasional shake up. Then pour off the clean liquid and spray on to the print as usual. It is better to give two or three very thin coats rather than one heavy one. Definition with Enlarger. I have an enlarger with an f/8 lens. When I focus with a lined negative the lines are clear only in the middle, and fuzzy round the edges. Why should this be so with such a small aperture as f/8 ? The enlarger is only made of wood, asbestos lined. S. W. H. (Hastings.) The fact that you get bad definition with your enlarger is certainly not be¬ cause the apparatus is made of wood. The obvious trouble is with the lens. It evidently has not a flat field, so that if you get the middle sharp the margins are fuzzy, and vice versa. You should aim at getting the sharpest definition between the middle and the margins, and then you will not have to stop down so much, but probably the only satis¬ factory course will be to get a more suitable lens. Choice of Camera. I give a description of the sort of camera I want to buy. Will you recommend a particular model, and tell me where it can b e obtained in London ? G. I. P. (Whitstable.) We never recommend one particular camera in preference to all others of the same kind. There are scores of different cameras on the market that would fill your specification. This you can find out by consulting advertisements and catalogues, but the actual decision must be left to yourself. Exposure with Telephoto. I have a reflex with a telephoto lens. If I ascertain the exposure with the ordinary lens, will this be correct for the Telephoto, or should it be shorter on account of distance ? R. H. (Norwood.) The only difference likely to be made in exposure is that with the longer focus lens you may cut out some heavy fore¬ ground shadows which would come into the subject with the shorter focus lens. Apart from this consideration there is no need to trouble about any difference at all. 28 142