Amateur Photographer & Cinematographer (1933)

December 6th, 1933 fa AMATEUR PHOTOGRAPHER p 6 CINEMATOGRAPHER a |etters to the Editor The Editor is not responsible for the opinions of his correspondents. “ PHOTOGRAPHIC SOCIETY ” or “ CAMERA CLUB ” ? Sir, — I often wonder how far the name " Photographic Society ” acts as a deterrent to young amateurs who might easily be gathered in by the more sociable expression " Camera Club.” In my own case, as a raw but not unenthusiastic tyro, I was for years prevented from approaching/the local “ Photo¬ graphic Society ” by no more than its learned name, being under the impression (false, no doubt) that my ignorance and cheap equipment would find no welcome within that august body. It would be interesting to know if any photographic society has ever considered seriously the psychological significance of its name to the extent of wishing to convert itself into a camera club ; and, having taken the plunge, if this has been followed by a more sociable atmosphere among the members and a greater readiness on the part of beginners to come along and join the happy band. — Yours, etc., " NINNY.” PLATE SIZES AND DEFINITION. him 2s. 6d. per dozen, and when his film packs did not break the back of half a sovereign. It is no surprise to him to know that the latest film pack is not made in the larger sizes, and that even the cost of smaller packs is scarcely known. Enlargement of small films and plates is referred to as a compromise, a recompense, or a way out, but enlarging involves additional outfit, material and time, and a further drain on pocket-money, which the amateur is most anxious to avoid. With the ever-increasing popularity of the motor-bike, the car and the bus, the weight of the hefty half-plate does not now count. The only thing that does count is " price,” and this has a firm grip on the amateur. Should he ever relax his grip, the postcard, 5X4, and the half-plate will be seen again. Then there will be no need for the snapshotter to provide his friends with magnifying glasses to inspect his results. One well-known firm appears to see possibilities of a return to larger cameras, and, let us hope, at more reasonable prices, which the working-class amateur will be able to meet. May it be soon ! — Yours, etc., “ HOPEFUL.” Sir,— May I enter the discussion on plate sizes with a view¬ point not yet discussed ? To begin with, my personal preference is for a 3JX2I, and I always use the largest aperture I can without getting the important parts of the picture fuzzy. As I usually enlarge to J-plate, this means real sharpness. The essential in any print is to get the right angle of view, and this is not a question of plate size, but of the ratio of the plate size to the focal length of the lens. Again, the depth of definition, which is of great importance in any attempt at pictorial effect, is a function of the focal length of the lens, so that the size of plate is again of secondary importance. To take an example, assume that the nearest point of interest is 10 ft. from the lens, and the farthest 200 ft. f have calculated the aperture necessary to give a circle of confusion of i/iooth in when enlarged on a halfplate paper with three sizes of negative, and the same angle of view. Negative size. Focal length of lens. Stop. 3x4 cm. . . . . . . 2 in. F/8 3^ x 2 1 in. •• 4T in . F/20 8j x6| in. . . . . ... ioj in. F/44 A moment’s consideration of the table will show that the exposure for any subject, when the lens is stopped down to give a definite depth of definition, varies as the area of the negative, which fact probably accounts for the excellent high¬ speed work produced by users of small cameras. As grain seems to be non-existent nowadays, if one can judge by the demonstration prints produced by makers of miniature cameras, the odds seem to be all in favour of the smallest camera procurable, as this will reduce exposure, and consequently enable one to get many pictures which would otherwise be lost. The only difficulty now would seem to be the designing of a lens to work at f/.5. — Yours, etc., H. MOORBY. PHOTOGRAPHIC BRASS TACKS. Sir,— Amateur photographers hear much about the demand for the smaller type of camera. Is there a real desire for the miniature type, or is it rather a simple case of “ Hobson’s Choice ” ? When an enthusiast looks longingly into a shop window for a camera of the old familiar size, such as postcard or half¬ plate, he will be lucky to find one. If he does, the doubled and trebled prices will stagger him and eventually compel him to ease the pressure of his nose against the plate-glass. Gradually, reluctantly, and with a last look at the increased cost of other material, he moves away, wondering the while whether the love for the large type of camera died a natural death, or whether it was killed outright by “price” In any case, price compels him to hang on to his old camera, and the cheaper class of plates and papers he is now used to. His one con¬ solation is to remember the day when his anti-screens cost EXTINCTION EXPOSURE METERS. Sir, — As I pointed out in a letter to “ The A.P.” some time ago, I also found the drawback with photo-electric and ex¬ tinction exposure meters was the fact that they varied the amount of exposure by the amount of light reflected by the object rather than that falling on it. Mr. John R. Talbot may overcome this difficulty by hanging a white object such as a handkerchief on part of the subject to be photographed — be it a grey and black piece of card or a cathedral — and examining it through the extinction meter at a distance of about two feet. It is important that the hand¬ kerchief is placed so that it receives the average illumination, and also that it is not shielded by the head of the observer. If the resultant reading is found to give over or under¬ exposure, it will merely be necessary to decide on a factor for dividing or multiplying the exposure indicated which will hold good for all future readings. In my own case, if I want, say, to photograph a street scene, in sunlight and shade, I stand in an open part of the shaded portion and hold a white postcard at eye-level tilted slightly towards the sky and about six inches in front of my “ Bewi ” meter, and double the indicated exposure. If it was an interior I should place a handkerchief over the back of a chair and again double the resultant indicated exposure. — Yours, etc., _ A. R. TURPIN. KEEPING QUALITIES OF PLATES. Sir, — Recently, at a local sale-room, I purchased two assorted lots of old photographic materials. When I got home and was sorting out the stuff I found three boxes of Paget XXXXX quarter-plates which had not been opened and, judging by other articles, were rather old. I loaded the slides of my quarter-plate camera with some of these plates, and went out and made a few exposures to see what they were like, and was very much surprised at the result. I wrote to the makers enclosing the box, asking if they could tell me when they were made. I have had a reply from Messrs. Ilford, Ltd., who say they have asked some of the old Paget Prize Plate Co. employees, who are with them, and they are of the opinion, although they cannot be 'sure, that the plates were made in 1904. They say it may not have been till 1914, as another box I have has that date on it. In the former case the plates would be twenty-nine years old. I enclose a negative made on one of these old Paget plates, and a print from it for your inspection. Other readers of “ The A.P.” may hhve had similar experiences of the keeping qualities of dry plates.— Yours, etc., L. A. LEWIS. [The negative sent by our correspondent is of first-rate quality, clean to the edges and of a good black-and-white character, with full range of gradations. It includes some fine cloud forms in addition to strong foreground objects. It is an excellent testimony to the keeping qualities of the old Paget plate. — Ed.] 3 8 530