Amateur Photographer & Cinematographer (1934)

December 5th, 1934 iHi AMATEUR PHOTOORAPHER ta 6 CINEMATOGRAPHER o ^Deaders' Questions ^ ANSWERED General. — All communications for the Editor should be addressed ; “ The Editor, The Amateur Photographer uryi Cinematographer^ Dorset House, Stamford Street, London, S.E.r,” 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 ver>' legible handwTiting on one side of the paper only. Letters or lommunications 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 bv a stamped wrapper or envelope can in no case be returned. Reproduction fees for prints are only paid bv arrange¬ ment beforehand. The sending of a print, without any condition stated, will be taUen 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 complv with the rules must be ignored. (i) See “ General ” above. (2) Every question and ever^' print for criticism mus't 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, (p) 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 “ Querv ” or ” Criticism,” as the case may be. (7) Prints are sent for advice or criticism on the distinct understanding that by so doing pernaission 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. M.O for Gaslight. Will you give me an M.Q. developer suitable for developing gaslight prints ? S. C. (London.) With any paper you buy you will find instructions for its use, and these will almost certainly include such a formula. A typical all-round solution for the purpose is : Metol 8 grs. Hydroquinone • • 30 grs. Sodium sulphite . . f oz. Sodium carbonate •• 1 oz. Pot. bromide (10 p.c.) 20 min Water 10 oz. Rytol. I have seen several references to Rytol as a developer. Can you give me suitable formulre for developing negatives and prints respectively ? W. B. T. (Dubhn.) Rytol is a complete developer in itself, and is made in tabloid form by Messrs. Burroughs Wellcome. Any photographic dealer can supply it. The tabloids are dissolved in pairs in a quantity of water suitable for the purpose in hand, and instructions on this point are given on the carton. Fuller information on the use of this developer is contained in the Burroughs Wellcome Diary. Focal-plane Shutter. I am told that a focal-plane shutter is more eflScient close to the plate than if it is farther away. Why should this be so ? One would think that the same amount of light would pass through the sh't however far from the plate it was. T. W. (Bingley.) We regret that we cannot enter into a lengthy scientific explanation of the efficiency of focal-plane shutters, but you may take it that the fact stated is correct. It may be sufficient if we point out that if you had the focal-plane shutter close behind the lens, using a narrow slit, the full aperture of the lens would at no time be operating. Medium for Prints. Some time ago you published a formula for a mixture for rubbing into prints. Can you repeat it ? What should I mix with the pigment for darkening ? W. I. B. (Sydenham.) You might first rub the following mixture well into the print with cotton¬ wool, and afterwards remove as much as possible with clean wool : Mastic varnish one part, linseed oil one part, turpentine two parts. You can then apply the pigment, thinned down either with the same medium or with any other medium suitable for oil painting. Flashlight Failure. In the enclosed flashlight group why are aU the faces featureless ? M. B. T. (Wallingford.) It is pretty evident that the trouble with your negatives is that the faces were not only exposed to the full effect of the light, but that the amount of powder used caused over-exposure. If you reduce the amount of powder and see that the light does not fall so fully on the faces you should get much better results. Book for Amateur. Can you recommend an all-round book giving practical hints on carrying out the various opera¬ tions undertaken by the amateur ? E. L. J. (London.) There are many books which would give you the information you want, and we have confidence in recommending “ Photography Made Easy,” by R. Child Bayley, price 2s. 3d. post free from our publishers. Finger-Print. Is it possible to remove a finger-print from the emulsion side of a negative ? A. G. J. (Finchley.) If you mean that the finger-print is due to pressure on the soft gelatine there. is no possible means of removing it. In some cases retouching may be a remedy. Lantern as Enlarger. Can a standard size projection lantern with a i2-in. lens be used for enlarging from 3^X2^ negatives ? F. C. (Huddersfield.) Speaking broadly, it is not possible to have any instrument that is equally suitable for enlarging and for projection, as the requirements in the two cases are so different. As the condenser of the lantern will probably cover your negative there is no reason why you should not put such negatives in the carrier. With a 12-in. lens, however, you will find the distances for enlarging are too great to be convenient, and you will probably find also that there is not sufficient scope for adjustment of the illurainant. It would help matters if you substituted for the projection lens a shorter focus lens which would satis¬ factorily cover the size of negative being used. Making Slides. I want to make a collection of lantern slides from my negatives. Should I make them on glass or film ? What size should they be ? W. J. H. E. (Ammon.) You will have to make your lantern slides on proper plates made for the purpose, the size being 3J in. square. You must get some guidance as to how to set to work, and we suggest that you obtain the N.P. Handbook, No. 6, Lantern Slides,” by Dr. B. T. J. Glover. This is published at is., plus postage, and you can get a copy from Messrs. Sands Hunter & Co., Ltd., 37, Bedford Street, Strand, London, W.C.2. Hardening Prints. When glazing prints what should be the strength of the alum solution for hardening the prints ? How long should the prints remain in the solution ? M. H. H. (Godaiming.) We think you will do better to use formalin rather than alum for hardening your prints. Buy some ordinary com¬ mercial formalin solution, and use one ounce of this to 9 oz. of water. At the end of the final washing give the prints about three or four minutes in this solution, keeping them moving all the time, and transfer straight to the glazing slabs without further washing. The solution can be used repeatedly. Modifying Prints. On the enclosed print you will see that details in the background spoil it. Can you give me a method for removing them ? T. A. T. (Derby.) We should strongly advise you not to attempt to deal with the prints, but to have the modification made by skilful retouching on the negative, a matter which can be dealt with at a reasonable price by a professional retoucher. Contrasty P.O.P. Can you recommend a P.O.P., self-toning or not, which is appreciably more contrasty than Seltona Vigorous ? T. H. M. (Sutton.) It is not practicable to secure the same variation as to soft, normal and vigorous grades with printing-out paper, although it is easy in the case of bromide and gaslight paper. We regret that we know of nothing that will meet your requirements. The only course in this case is to make negatives suitable for the paper. 22 524