Amateur Photographer & Cinematographer (1935)

July 24th, 1935 Thi amateur photographer ft 6 CINEMATOGRAPHER o ‘Deciders' Questions ANSWERED General. — All communications for the Editor should be addressed : “ The Editor, The Amateur Photographer ana 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. AH rontribu'ions 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 are not paid for. 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 foe. Enquiries and Criticism. — Advice, Criticism and Information are freely given, but the following conditions Tjould be read carefully before applying, as anv 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 'o this rule t-xcept 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 'O 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 trom the latest issueto reach the eno uirer Dull Negative. Can you explain the grey dull appearance of the enclosed negative ? E. R. (Rochester.) We do not quite understand what you mean by the grey dull appearance of the negative, as, apart from slight stain, it is quite a good one. You are pos¬ sibly not aware of the fact that Verichrome film has a matt surface and therefore does not have quite the clear, transparent appearance of other films. Liquid Safelight. I am making a safelight of two glass globes with a lamp in the inner one. Will you give me a formula for a solution suitable for the loading of ordinary plates ? E. H. (Willaston.) Dissolve 2 oz. of potassium bichro¬ mate in 20 oz. of hot water, then add 1 gramme of Eosin. Stir thoroughly and allow to cool. You will almost certainly find a slight sediment. Decant the clear liquid, add three or four more ounces of water, and filter. The solu¬ tion is then ready for use. Titles of Prints. In the criticism of a print hv “ Mentor ” to what extent is the percentage of good marks from the artistic asDect influenced by the aptness or inapt¬ ness of the title ? L. H. J. (Acton.) We find it difficult to give any definite answer to your question. We should say, in a general way, that the title does not influence the criticism, unless the title itself suggests some particular idea or aim of the photographer which has obviously not been achieved in the result. The title would then be in¬ appropriate. Some of the best pictures do not need a title at all. Proportions in Developer. The quantities given for amidol developer seem to differ considerably. What is the effect of having too much or too little sulphite or bromide ? T. M. P. (Folkestone.) There is considerable latitude in the proportions of amidol developer, and if you adopt any one of the standard formulae there is no reason why you should have too much or too little of any one constituent. In our own practice we sometimes omit bromide altogether for bromide paper, and, as far as we can see, the omission does not lead to fog or any other trouble. The best plan with any given paper is to adopt the proportions given in the instructions. Paramidophenol. I do not want a concentrated paramidophenol developer, but one to make up as required for use. Can you help me ? C. E. P. (Caracao.) Here is a formula which should suit you : A. Paramidophenol . . 200 grs. Potassium metabisul¬ phite . . . . . . zoo grs. Distilled water to 20 oz. B. Sodium sulphite .. ij oz. Potassium carbonate . . i| oz. Distilled water to 20 oz. For use take one part of A and two parts of B, mixing thoroughly. Temperature. I have noticed in “ The A.P.” several references to temperature, and yet you don’t mention it in the article on development and printing. Does it refer to the developing solution or the washing water ? A. N. (Burton.) We cannot quite understand your letter. When temperature is referred to it means the temperature of the develop¬ ing solution, and is only of importance when negatives are developed for a certain time without inspection. It has no reference to the washing water. Smashed Lens. I smashed the back element of a lens, and a local workman who tried his hand at it has made matters worse. Can you tell me of a firm who will undertake to repair such a smash ? C. McL. (Edinburgh.) It is quite impossible to repair a smashed lens, and the only thing is to replace it. As far as we are aware this particular lens is no longer on the market, and we cannot now trace the firm who used to manufacture it. You might communicate with the Premier Optical Co., Ltd., 63, Bolton Road, Stratford, London, E.15, who might be able to replace the broken element, but we think it likely that you will have to regard the lens as a loss. Drying Plates. Can you tell me how to dry plates quickly after development ? J. E. D. (Leeds.) There are several ways of drying plates quickly, but it is not easy to condense the information. One method is to immerse them for a few minutes in two successive baths of methylated spirit, after which they dry very quickly. At the same time, this is likely to cause stains and other defects, as the spirit is not likely to be pure. Another method is to treat the plates with, say, a 5 per cent solution of formalin and surface-dry them, after which moderate heat can safely be used in drying them. Choice of Camera. I have seen demonstrated the two cine cameras of which I give a brief specification, but as there is much to be said in favour of each I cannot decide which to choose. Can you advise me ? J. R. (London.) The difficulty which you find in de¬ ciding which apparatus to select applies also to us. As you rightly say, there is something to be said for each of them ; they are both good value for money, both the firms are reliable, and both the instruments give excellent results. We do not think that the choice between the two is a matter of any real importance. Permanence. What kind of printing paper is likely to produce the most permanent results ? How long should prints last if stored in an album ? N. W. D. (Chertsey.) Platinotype paper is possibly the most permanent printing process, as the image will last longer than the paper itself ; but it is very expensive. Carbon paper, either in the original form or worked by the Carbro method, may also be regarded as permanent with most of the pigments used. Ordinary bromide and gaslight prints, if properly produced and kept under favourable conditions, should last a quarter or even half a century. Fogged Negative. All my films show fog like the one enclosed ; can you suggest the cause ? E. W. (Pembroke.) Your camera is evidently letting light leak in, and we can only suggest that you send it with the negatives to a firm of repairers, and ask them to locate and remedy the trouble. Filter Factor. I have a yellow filter marked “ Korelle mittel.” What is its exposure factor ? W. S. O. (Craigavad.) You are apparently not a regular reader of the paper or you would have seen that we have frequently drawn attention to the fact that no light filter has one invariable factor. The factor varies considerably according to the emulsion with which the filter is being used, and must be found by trial. 42 102