Amateur Photographer & Cinematographer (1933)

October nth, 1933 Ihi mTURNCTCGGAPHER I p 6 CIMEriATOfliyJHEP o 1 ‘Deciders' Questions •^V ANSWERED General. — All communications for the Editor should be addressed : “ The Editor, Jhe Amateur Photographer and Cinematographer, Dorset House, Stamford Street, London, S.E.i ” 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 handwriting on one side of the paper only. Letters or communications arising out of matters already appearing in the paper are net 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 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 cf 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 tc reach the enquirer. Oil Colouring. I have tinted several photographs with water colours. Is it possible to me oil colours ? What surface of paper is best ? Is there a book on the subject ? H. C. (Spondon.) It is certainly quite possible to colour prints with oils, for which purpose it is best to use a matt or rough surface paper. We know of no book which deals with this subject only, but the matter is re¬ ferred to in " Retouching and Finishing for Photographers,” by J. Spencer Adamson, obtainable from Messrs. Henry Greenwood & Co., Ltd., 24, Wellington Street, Strand, London, W.C.2. Stained Negatives. Can you tell me the cause of stain and fog on the enclosed negative ? They did not show till the milkiness of the film had cleared in the fixingbath. L. A. C. P. (Muswell Hill.) We should say that the whole trouble with your film is insufficient fixation before the film has been exposed to light and air. You talk about the milkiness having cleared, but it is evident from your negative that it had not cleared at all. You should leave the negative in the fixing-bath until it has quite cleared, and then for as long again, before exposing it to actinic light, and to air. Bolting Silk. How can I affix bolting silk to glass to make a diffusing screen ? Should the silk be black or white ? L. C. H. C. (Caterham.) You do not say whether you propose to use the bolting silk actually in contact with the printing paper or at varying distances from it. The best way of affixing the silk to the glass is to run a narrow line of adhesive round the edges of the latter, lay the glass on the silk, and put it under pressure until dry. Bolting silk is always white, and you are probably thinking of chiffon when you mention black. Glycin. I often see glycin mentioned in your pages, but can find no particulars of it anywhere. Has it any particular advantages ? Is there any book about it ? G. A. J. (Aberdare.) Glycin is a very familiar developing agent, and particularly useful for tank development when considerable dilution is required. There is no special book about this particular developer any more than about any other of the scores of developers available. All you re¬ quire is a formula for making it up. It has a tendency to give soft and delicate images very similar to those obtained with metol. A typical formula is : A. Glycin . . . . . . 96 grs. Sodium sulphite . . 1 oz. Water to ... 20 oz. B. Potassium carbonate 2 oz. Water to . . 10 oz. For use take two parts A to one part B. The price of Glycin is about 2s. 6d. an ounce. Correct Exposure. I send a print with foreground in shadow and distance in sunlight, and give particulars of exposure. What should have been the correct exposure to get a clearer print ? H. W. T. (Bramhall.) As far as we can judge from the print the exposure you gave was as near right as could be. The trouble is that the very dark foreground required much more exposure than the extreme dis¬ tance, and it is very difficult to adjust exposure and development so as to get both approximately right. You did not send the negative, but it looks as though this had been a little over-developed, so that the sky and the distance are too dense. Some improve¬ ment would be made by giving additional graduated exposure to the upper part of the subject, so as to bring out more clearly the distant hills, and to give some tone to the sky. Light Filters. I want to prepare some light filters. Have you had an article on the subject ? Can you put me in touch with a firm supplying optical flats, which I understand are inexpensive ? j. G. (Detling.) Although we gave some brief informa¬ tion about light filters recently the matter is so wide and technical that you will require much more information than we were able to give. You will find the matter more fully dealt with in the " Dictionary of Photography,” pub¬ lished from this office. Optical flats are the most expensive form of gla«s possible for making filters, but you can get particulars as to prices of different sizes, and also as to the neces¬ sary dyes for filter making, upon application to Messrs. Ilford, Ltd., of Ilford, London, E. Night Pictures. What is the approximate exposure for photo¬ graphing the illuminations at Blackpool and Morecambe ? H. A. (Batley.) We have often pointed out that it is impossible to give even approximate exposures for artificial illumination. This work depends upon so many factors that it is quite useless to make even a rough suggestion without knowing them all. Your only chance is to make experiments upon the actual subject, giving exposures from, say, ten seconds up to a minute, at full aperture, and then studying the results. If many of the lights are red, deep yellow, or green, you are not likely to get very satisfac¬ tory results except with panchromatic material. < Flower Photography. I want to take photographs illustrating the culture and growth of certain flowers, including closeups. What type of camera and lens shall I require ? What background should I use in taking, say, a single flower ? J. G. V. (Beckenham.) For the kind of work you describe you will certainly require a focussing camera, and we would suggest one of the ordinary field type, with a long extension, so that with a lens of normal focus you could photograph objects natural size if required. A good anastigmat working at f/4.5 would be an advantage. You do not say whether you are going to work out of doors or in, but, if the latter, it is a simple matter to set up a background in the shape of a sheet of cardboard of suitable tone. This, or a screen of fabric, can also be used out of doors. The whole question is much too complicated to be dealt with in the form of a reply, but you will undoubtedly need panchromatic plates or films, and, in most cases, a suitably adjusted colour filter. Methylated Spirit. Will the colouring matter used in methylated spirit stain my plates ? I always immerse negatives in spirit to dry them quickly. J. P. O. (Colombo.) We think it very likely that the colouring and the general impurity of methylated spirit will not be good for your negatives, if they are valuable, but for rapid results it is the readiest method available and is extensively practised by Press photographers. 24 345