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June 14th, 1933
thi amateur photographer
p 6 CIHEMATOGRAPHER a
‘Deader^ Questions
A_ ANSWERED
Ofni hat,. — All coinniimic.itions tor tlic Editor slioulcl be addressed : " ITie Editor. The Amateur TIintographei oti'i Ciitemafoerapher. Dorset House, Stamford Street, London, S.E.i,” and in every case, without exception, must eivc 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 p.aper only. Letters or communications arising out of matters already .appearing in the paper are not paid for. The Editor disclaims legal rcsponsihilitv 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 enr elope 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.
Fnouiries and Criticism. — .Advice, Criticism and Information are freely given, but the following conditions shoulil 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 inaiile in any case to this rule, except so f.ar as enquiries or prints from Overseas are concerned, (p) Neither enquiries nor prints for criticism must be enclosed with competition prints. (4) On the back of each print sent for criticism, in adiiition 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 he 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 oi 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 tne current number, and should be cut from the latest issue to reach the enquirer.
assuming that all the processes have been carried out properly, and that the prints are not exposed to any extra¬ ordinary treatment or conditions of keeping.
Photographing Silver.
I have been asked to photograph a silver cup, and to cut down to the minimum the reflections. How can this be accomplished ?
D. H. S. (Hastings.)
The best way of damping down the reflections of a silver cup is to illuminate it only by light passing through tissue paper or some similar medium.
Copying.
What plates should be used for copying black-andwhite subjects, the paper sometimes yellowed by age ? What exposure should be given with magnesium ribbon ? Is M.Q. suitable for de¬ veloping ? A. R. (Truro.)
Process plates or films are the best for copying black-and-tvhite subjects, al¬ though they may have to be of the orthochromatic brand if the paper is yellowed. The exposure must be found by experiment, taking care to burn the ribbon at the same' distance from the subject. M.Q. is quite suitable for developing such negatives.
Image in Monochrome.
Is there any means of rendering the image on the focussing screen of a reflex in monochrome ? I do not want to use a filter on the lens or affect its light-transmitting property.
H. M. M. (Kensington.)
We know of no possible method by which you can convert the image on a focussing screen into monochrome. If it is looked at through blue glass this subdues the colours, hut, at the same time, greatly reduces the luminosity.
Black Background.
How can I get a black background on a picture of a person taken from a group photograph ?
J. D. B. (Wellingborough.)
There are several ways of arriving at the sort of thing you describe, but there is not one of them that can be explained adequately within the limits of a reply. It may be a useful hint if we say that you could make an enlargement of the figure you want, paint the background black, and re-photograph. This, of course, requires con^derable technical skill.
Enlarging.
Having no experience of enlargers could you recommend any particular make ? Does an enlargement have to go through the same process as prints ? H. C. (Blyth.)
The best advice we can give you is to get a handbook which will give you the information you require. Such a one is " Photographic Enlarging,” by K. Child Bayley, obtainable from our publishers, post free, price 3s. 3d.
Enlargements are practically always made on bromide paper, which has to be developed, fixed, and washed.
Types of Cameras.
Would you tell me the type of work for which the following types of cameras are most suited : reflex, press, ordinary roll-film and miniature ? Has a quarter-plate camera an advantage over a smaller one ? W. .A. W. (Bromley.)
The use of any particular type of
camera is largely a matter of personal taste. With any one of the four an experienced worker would turn out an enormous variety of work, and no one would be able to tell from the results which sort of camera he had used. You cannot compare a quarter-plate camera of one type with a smaller camera of another. If the two cameras are identical except in size, the only advantage of the quarter-plate is that it gives a larger negative. On the other hand it w'ould be larger, heavier and more expensive to buy and to run.
Choice of Meter.
Of the three meters named, which one would you advise me to choose ? D. H. E, (Crewe.)
There are no grounds on which we can advise you to select one of the three meters you name in preference to the other two. We have ourselves used them all. and if we had to be restricted to one we should not mind in the least which one it was.
Defective Negatives.
The enclosed films were professionally developed. The sun was obscured at the time of exposure, and the camera was a reflex. Can you..advise as to the faults in the negatives ?
W. B. (Kingston.)
The defects on your negatives have nothing whatever to do with the de¬ velopment, nor the fact that the sun w'as obscured at the time of exposure. The faults appear to be due to defects in the camera itself, and we should advise you to have it examined and overhauled by the makers.
Toned Prints.
I have been toning gaslight prints with sulphide. May I expect these toned prints to last as long as ordinary gaslight prints ? D. E. (Rugby.)
It is definitely claimed that prints that are sulphidp-toned have a longer life than if they had remained in their ordinary condition. This is, of course.
Development Times.
I have been used to dish development with the formula quoted herewith. How much of this solution should I take to make 40 02. of dilute solution for a tank, and how long would develop¬ ment take at 65 degrees ? G. V. C. (Halifax.)
We regret that we cannot give you definite answers to jmur questions. To begin with, we are surprised that you are going to use a tank that requires 40 oz. of solution. The more you dilute the stock solutions the longer will be the development time, and you must really find out by experiment what that time is to suit the particular films you are going to use, and to produce the kind of negatives you require. Even at the same temperature, and with the same .solution, development times vary very considerably for different sensitive ma¬ terials. Probably your best plan will be to make up a dilute solution, and then, by dish development, find how long it takes to develop, taking all the conditions named into account.
Depth of Focus.
In Mr. Child Bayley’s book on hand cameras he explains how to find the hyperfocal distance and depth of focus. His results do not agree with those given in another published table. Would you set me straight on this ? F. P. F. (Toronto.)
The differences found in depth-offocus tables are generally due to a differ¬ ent circle of diffusion being adopted. You may absolutely rely on the methods described in Mr. Child Bayley’s book,, although you can alter the permissible amount of diffusion to suit yourself.
Safelight.
Can you give me a not too expensive formula for a safelight coating on glass, safe for developing films ' N. E. (Bristol,)
The making of safelights by coating glass is not one that can be dealt with briefly. The subject is one that must be studied from textbooks. If you want only one safelight it would be cheaper and safer to buy one.
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