Amateur Photographer & Cinematographer (1933)

iHf AMATEUR PHOTOORAPHER 1 p 6 CINEMATOGRAPHER o I March ist, 1933 ^Deaders' Questions ^ ANSWERED General. — All communications for the Editor should be addressed : “ The Editor, The Amateur Photographer and Cinematographer, Dorset House, iTudor Street, London, E.C.4,” and in everv 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 typeviTitten, or in very legible handwriting on one sidfe of the paper only. Letters or roinmunications arising out of matters already appearing in the paper are not paid for. The Editor disclaims legal responsibib'ty 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 reproi\ice 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 w'fth the rules must be ignored. ^ (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. (•^) 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 writte^ 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 answ'er 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. Modifying Negatives. I am told that rather flat, weak negatives can be duplicated in a stronger form by means of a transparency and a new negative. If this is so, how is it done ? M. L. (Exeter.) We can give you only a brief outline of the procedure. You first make, by contact printing, a transparency on a slow ordinary plate. You can so ad¬ just exposure and development as to get all the necessary “ pluck ” into the result. You then repeat the procedure, using the positive to print from, and at this stage you can also increase contrast if necessary. Full exposure and shortened development tend to softness ; minimum exposure and full development to contrast. Local Toning. I have seen a print on self-toning paper in which part of the subject was of a browner colour than the rest. What is the method of doing this ? G. M. W. (Norbury.) If self-toning paper, after the pre¬ liminary washing, is placed for some time in a strong solution of common salt, this gives a colder tone than if the print is put straight into the hypo. Instead of putting the print bodily into the salt solution you can use a brush and paint the solution over those parts of the subject that are required to be colder in tone. The method is of very limited utility. Copper Toning. Some years ago I used a two-solution copper toning bath with pleasing results, but cannot now find the formula. Can you supply me with one ? J. S. (Harrow.) A well-known form of this bath is : A. Copper sulphate . . . . 6o grs. Potassium citrate . . 240 grs. Water . . . . . . 20 oz. B. Potassium ferricyanide . . 50 grs. Potassium citrate . . 240 grs. Water . . . . . . 20 oz. The working solution is equal volumes of A and B. Mounted Transparency. I am sending a passe-partout print which puzzles me, as I have never seen a paper of the kind. Can you tell me what make it is ? A. M. M. (Oxford.) We feel pretty certain that this is not a print at all. It is almost certainly a transparency on a photographic plate. The paper behind it would be ordinary (not sensitised) paper, probably got into optical contact with the plate by means of a solution of gelatine. The method is a fairly familiar one, and, given the correct quality in the transparency, very effective. The image is brilliant, and any sort of paper can be used for backing it. Developing Films. Can I develop an film pack with an ordinary M.Q. developer ? Will you please give me some hints on developing ultra-rapid films ? S. R. (Weymouth.) It is always better to use for any given sensitive material the formula recom¬ mended by the makers. At the same time, there is no reason why M.Q. should not give you e.xcellent negatives on the films you name. We cannot think of any hints to give you on the subject. If you meet with any special difficulty we shall be pleased to help you to solve it, but we cannot offer hints at random without knowing exactly what it is you wish to know. Book on Press Work. Is there a reference book giving addresses of papers and magazines likely to accept photographs for reproduction ? A. B. B. (Exraouth.) There are several books of the kind you mention, one being “ The Writers’ and Artists’ Year-Book,” published by Black. Another book is " Photographs for the Papers,” by John Everard. We think you could obtain these and other books on the subject upon application to the Westminster Photographic Exchange, Ltd., of III, Oxford Street, London, W.i. H. & D. Can you give me any information concerning the H. and D. system of estimating plate speeds ? P. C. F. W. (London. A complete account of the methods of Messrs. Hurter & Driffield is printed in a book published by the Royal Photographic Society at 25s., so that you may guess it is not a subject that can be .dealt with in the form of a reply to a question. Camera for Copying. What make of camera is suitable for the varied requirements of copying ? J. R. D. (London.) The essentials of a camera to make it suitable for copying are that it shall have a focussing screen, and a sufficiently long extension to carry the lens twice its focal length from the plate in order to be able to copy same size. It is also an advantage that the camera shall have back focussing as well as front focussing. If the camera can be arranged to move backwards and forwards on a baseboard, at one end of which the easel is attached, this is all to the good. An anastigmat is the best type of lens for the purpose. Contributions . I intend to submit an article to you for publica¬ tion. Must it be typed ? What size prints do you require ? Must they be on glossy paper ? Can you give me an idea as to payment ? Do you pay for cover subjects ? Must these be in colour ? R. T. (Rhyl.) Articles submitted to this paper may be in manuscript provided the writing is easily legible. There is no regulation as to the size of the prints, as if they are too small we can borrow the negatives if we require them. Strong prints on glossy paper are generally advisable. Our ordinary rates for contributed articles that are not specially commis¬ sioned are £i is. per page, irrespective of whether the space is filled with letterpress or illustrations. For photographs used for the front cover a fee of £i is. is paid : they should, of course, be in monochromp. Exhibition Awards. What is the advantage of having prints exhibited at the Salon, the R.P.S., etc ? Are prizes given to the winning prints, or what ? J. M. (Glasgow.) The exhibitors at the London Salon and the R.P.S. do not compete for prizes,' but show their work as a matter of general interest to advanced photo¬ graphers and picture lovers generally. At some other exhibitions which have open classes awards are offered, but these can, of course, be secured only by very capable workers, as the competitior^ is always keen. Bromide Printing. Could you tell me the procedure to be adopted when making contact prints on bromide paper ? Can you suggest a book of instructions for the novice on such matters as developing an<l print¬ ing ? D. J.C. (HuU.) It is clearly impossible to deal fully with the question of bromide printing as a reply to a question. A book which will give you sufficient information both on this subject and on developing and other forms of printing, is “ Photo¬ graphy Made Easy,” by R. Child Bayley, obtainable post free from our publishers, price 2s. gd. 26 I 216