Amateur Photographer & Cinematographer (1933)

February 8th, 1933 ih( amateur photographer a 6 CINEMATOGRAPHER o General. — .All communications for the Editor should be addressed : " The Editor, The Amateur Photographer and Cinematographer, Dorset House, Tudor Street, London, E.C.4," and in every case, without exception, must give the name and address of the writer. Contributions. — The Editor is glad to consider original, up-to-date manuscripts on photographic subjects. .■Ul 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 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 starnped 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 (i) 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. (4) 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. Fogged Negatives. W'ill you explain the fogging and lack of definition in the comers of my negatives ? I send particulars of films, dark-room light, etc. G. R. VV'. (Dowlais.) The trouble with your negatives is nothing to do with the film or the dark¬ room light, and is not fogging at all. It is evident that for some reason or other some of the light which should form the image is not reaching the filnr at all, and it almost looks as though the lens is not covering properly. We doubt whether there is any possibility of tracing the trouble without examination of the camera you are using, and about which you give no particulars whatever. Intensified Negative. The accompanying negative is one of many made about twenty years ago. They were probably intensified vidth mercurv and ammonia, but have all faded. Can anything be done with them ? G. G. B. (Bury.) The negatives have reverted to the bleached condition. You might treat one of them as follows : Soak well and then treat with a 10 per cent solution of sodium sulphite until the image is blackened right to the back ; then re¬ wash and dry. If this treatment is successful you may safely proceed with the other negatives. You will find, if the enclosed negative is a fair sample, that they will be very dense', and will probably require a soft paper to get a satisfactory print. Faulty Negative. What is the cause of the clear margin at the ends of the enclosed negative ? D. W. D. (Worthing.) As might have been e.xpected, your negative arrived smashed into such small pieces that we could hardly find one showing the clear edge to which you refer. We cannot identify the cause of the trouble, but if you are using a camera with bellows^ it is quite possible that the back of the bellows interferes with the light reaching the plate. We may point out that if you wish to send a glass negative through the post it is no protection whatever to wrap it in cottonwool and to write " Fragile ” on the envelope. Stereoscopic Work. What advantage have staiiflard-size stereoscopic pictures over smaller ones ? Can I make stereo¬ scopic. pictures of flowers by two consecutive exposures ? Is there a book on the subject ? C. W. W. (Beeston.) Stereoscopic results do not depend to any extent upon the size of the pictures, and the smaller sizes look just as realistic as the larger ones. There is no reason why you should not take your flower studies in the way you describe, provided that the camera is moved for the correct distance, and that there is no movement in the flowers while the exposures are being made. .\ standard book on the subject is " Stereoscopic Photography,” by A. W . Judge, price 15s. net. Rapidity of Lenses. Is a short-focus lens faster than a long-focus lens ? If so, why ? H. B. (London.) There are two main factors which decide the rapidity of a lens. One is the f/ number ; and the other is the con¬ struction of the lens itself. The more glass-air surfaces there are in the lens the greater is the loss of light. The focal length does not necessarily enter into the question at all. Processing Films. Will you let me know the formula for prdcessing 9.5-min.. films ? F. .A. M. (Yannouth.) As we have frequently pointed out in our pages you require a great deal more than a mere formula to enable you to process cine films. The whole matter is fully described in " Motion Pictures with the Baby Cine,” by Harold B. Abbott (obtainable from our publishers, price 2S. 8d., post free). 136 Negative for Projection. I want to make a lantern slide from a negatii'e. How can I get the positive effect on the screen if a negative is fixed between two glass plates to form a slide ? C. B. R. (Coulsdon.) If you project a negative with an optical lantern you will, of course, get a negative image on the screen. Nega¬ tives are not used for this purpose at all, but positive transparencies made on lantern plates. As we pointed out in a recent article, if you can make a gaslight or bromide print you can soon learn to make a lantern slide. The method of doing this, however, can only be learned by studying the subject in textbooks or articles. Blacks on Bromide Paper. Can you tell me bow to get better blacks on bro¬ mide paper ? What causes a green tinge on chloro-broniide paper ? W. F. H. R. (Walton.) Your first question suggests that we can send you some definite piece of information which will enable you at once to get good blacks on bromide paper. This is, of course, impossible. The quality of the blacks depends upon the character of the negative, the kind of paper used, the exposure given and the development adopted. In regard to your second question, chloro-bromide paper, properly used, does not give greenish tones, and if you get such, you may take it that yoqr procedure is wrong somewhere or other ; but where, we cannot possibly guess. You may be using an unsuitable de¬ veloper, or over-exposing the paper, but we cannot say with certainty. Competition Rules. .As I shall shortly become a professional photo¬ grapher will this debar me from entering your monthly competitions ? J. A. (Cape Colony.) If you refer to the rules of our com¬ petitions you will find, that the very first line states that the advanced workers’ section is open to amateur photographers. This obviously excludes professionals, and naturally professionals would not enter the beginners' or inter¬ mediate sections. Selling Prints. I send a number of my prints. Would you advise me to send a number of glossy enlargements to an agency for sale in England ? •A. F. (Colesberg.) We have looked through your prints, and, although they are very good average photographs, there is nothing amongst them which we think you would hav^e the slightest chance of selling for reproduction in this country. There is scarcely any subject which an English publisher wants which he cannot obtain at once from the enormous stocks of English Press agencies. There is no market in this country for ordinary, everyday snapshots taken abroad. Iris Leaf. I enclose a leaf from an iris diaphragm. Will you tell me the name and address of the makers, and the price ? C. G. B. (Cardiff.) We do not know whether your question is intended as a joke, but you might just as well have sent us a horseshoe and asked us to name the horse that wore it. 24