Amateur Photographer & Cinematographer (1933)

March 8th, 1933 ihi amateur photographer p 6 CINEMATOGRAPHER a ‘Deaders' Questions ^ ANSWERED General. — All communications for the Editor should be addressed : “ The Editor, The Amaieitr Photographer and Cinetnatographer, 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. All contributions must be typewritten, or in very legible hand%vTiting 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, wnthout any condition stated, will be taken as permission to reproduce it without fee. Fncuiries 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, jg) Every question and every print for criticism must be sent separately through the rost, and must be accompanied by a separate stamped addressed envelope. No exception can be made in any case to this rule, except so far a* enquiries or prints from Overseas are concerned. (^) 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 w'ith 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 toreac^ the enquirer. Removing Backing. How and when should backing be removed from plates ? M. S. (Swansea.) There is no definite rule about the removal of backing from plates. It depends upon the kind of backing, and sometimes on whether the plates are to be developed in a tank or in a dish. In the latter case the backing often comes off entirely in the developer. This is the case, for example, with the new Ilford backing for their panchromatic plates. In other cases the backing remains through both developing and fixing, in which case it can be sponged off before the final washing, or even afterwards. If backing is to be removed before development, the plate should be held horizontally, back downwards, over a bowl of water, and the backing sponged off. The plate can then be rinsed in clean water before placing in the developer. Damaging Enlarger Lens.' I have been informed that in using a camera as part of an enlarger the heat is detrimental to the lens. Is this so ? E. R. E. W. (Crouch End.) You are not likely to have any such trouble as you anticipate. The only ordinary cause of trouble is when the heat is so great that it affects an iris diaphragm, the leaves of which are of thin vulcanite. Even with a condenser, however, this is not likely to occur with a properly constructed and ventilated enlarger. Testing Shutter. Can you describe a method of calculating the speeds of a T.-P. roller-blind shutter ? \V. C. G. (Bath.) We have from time to time published articles on methods of testing shutter speeds, but the full details cannot be compressed within the limits of a reply. A familiar method is to set up a gramo¬ phone with the turntable parallel with the plate, and with a small bright ball or circle attached to the rim. When the turntable is revolving once per second an exposure is made, the plate developed, and the arc traversed by the moving spot measured, making allowance for the diameter of the spot. You will notice that this is not an accurate method, as the spot will be moving against the shutter direction in one position, and with the shutter move¬ ment in another position. If you wind the spring of your shutter so that the blind just completes its journey, and then set the poin-ter on the dial to I /15th of a second, you will find the marked exposures sufficiently ac¬ curate for all practical purposes. Luminous Watch. I have a wrist-watch with luminous figures ; wilt these have any effect on plates during develop¬ ment ? G. E. N. (Beaconsfield.) Unless you go out of your way to bring the plates very close to the figures on the watch you are not likely to have any such trouble as you suggest. Infra-red Photography. Where can I get particulars about plates, etc., for infra-red photograrhy ? L. S. (Wallasey.) You can get all the information you require on infra-red photography upon application to Messrs. Ilford, Ltd., of Ilford, London, E. Portable Dark-room. Do you know of a firm making a portable dark¬ room ? I mean one that I could set up on a table and develop plates in daylight. H. B. (Spalding.) The sort of article to which you refer is almost completely out of date, and, in any case, could only be regarded as more or less of a makeshift. The nearest thing of the kind we have been able to trace is the Simplex Changing Tent, and we should advise you to get particulars of this from Messrs. Jona¬ than Fallowfield, Ltd., of 61—62, Newman Street, Oxford Street, London, W.i. High-key Prints. I send a negative and a print from it, showing the subdued tone I prefer. Do you think this style too flat, or would a more contrasty paper give a better rendering ? I develop the negatives for a little more than half the standard time. J. A. E. (Jamestown.) The negative you send is a good and clean specimen, and indicates careful technical work. It is, however, on the thin side, owing to the shortened develop¬ ment time. This means that you can easily get from it the soft grey print that you send, and if you wanted a stronger and brighter print you could get it from the negative by using a more vigorous grade of paper. This high-key style does not suh all subjects, and we think that the particular subject you send would have been much more effective in stronger tones. If you develop your negatives farther it will be easier to get more contrast and vigour into the print, and, at the same time, if you should want extra delicacy you can obtain it by using a softer grade of paper. Choice of Lens. Before starting on pictorial work I want advice about a lens. I thought of 13! in., and I intend to enlarge from halt-plate. Do you advise a soft-focus lens to get the diffused effect of the present school ? Or should I get an anastigmat and diffuse with bolting-silk, etc. ? S. C. L. (Birmingham.) You are making the fundamental mistake of supposing that so-called pictorial photography is dependent upon some particular lens, or on 'the method of securing diffusion ; and this, of course, is not the case. You speak of the diffused effect of the present school, but we cannot imagine what you mean by it. In some of the most modern photo¬ graphy the chief characteristic is the sharpest definition that can be obtained. You do not say whether you want your lens for enlarging or for making the negatives, and 13 J in. is very long for all-round work on half-plates. Although even a longer focus may be used at times, on other occasions it would be very awkward not to have a lens of, say, 8 or 9 in. If you intend buying only one lens we should definitely advise you not to make it one of the soft-focus type. You can easily diffuse the image of a sharp negative, but you cannot possibly sharpen up the image of a diffused negative. Choice of Camera. As an artist I want a small camera to take street scenes, crowds, and action pictures such as run¬ ning figures. Would it be possible to get one for 30s. ? J. L. (S. Wales.) To deal with what are known as high¬ speed subjects such as people running, you require a shutter capable of giving higher speeds than you can get with the shutter of any camera at a price like 30s. As regards the other subjects, we should advise you to look out for a 3-J X2| fold¬ ing roll-film camera. If you have had any experience in photography you should be able to secure what you want with such an instrurnent, especially as you say that the results can be enlarged. You must remember that such a camera will give good results only under bright lighting conditions, as the lens will be " slow.” 28 242