Pinhole Photography

New Zealand Times, Volume XXXIII, Issue 7979, 9 December 1911, Page 7

Pinhole Photography

How to Make the Camera. (Continued from Last Week.) PROCURE a box about the fiizo of a half-plate, ami about 12 to 14 inches lens:. I havo found tho above size to be n uch tho i)o.st, and have rnudo a negative storage box answer my requirements. This is already slotted to hold the plates, but must bo painted dead black inside to avoid reflections, and must be absolutely light tight. If it is not so, tho box hhould ho covered with American leather, a flap at ono end to button over, so that it may easily bo opened when required. Bore three holes in the trout of the box. ono io bo exactly in tho centre, cno I 5-8 inches to the right, and another I 5-8 inch to the left of the central hole (the outer holes are for stereoscopic work; If required, bore ono about ono inch above tho central hole, to answer tho purpose of a rising front, thus cutting oft’ unnecessary foreground in landscape work. A simple shutter cun bo made of cardboard. This should be so arranged that by eliding one way the central helo is uncovered, and by sliding tho reverse way, tho stereo holes are uncovered. When in its normal position all tho holes are of course covered up. Before proceeding with tho construction of the actual pinhole, it would be as well to boar in mind that the smaller the holo tho finer will be tho detail, but the longer tho time of exposure. Tho essentials of a good pinholo are that it ho made in very thin material, ho perfectly circular, and quite free from saw-like edges. The 'Tens*' plate cannot be too thin, for if ono considers the size of the aperture through which the light enters to form tho picture, it will bo readily seen that any appreciable thickness must effect tho quality of the pictures. Bough edges will act in a similar way, and often give a most distorted effect. . , f Tho method of making tho pinhole adopted ns most satisfactory, hy mysoa is ns follows: Procure a piece of tho thinnest brass obtainable, and place it on a square sheet of lead, then, with a blunted nail or tapered penholder, make a light indentation. Carefully rub down tho projections thus mado on a fine oilstone, and thus further reduco the 1 thickness. Take tho selected noodle aud , carefully pierce the brass in tho centre of tho 'impression, revolving the needle as it penetrates. Bo not proceed too far at first, but rub down the burred edges on tho -oilstone, then use tho needle again, and so on. Proceed thus until the needle will go right through tho holo. Work on one side of tho brass only, and be careful'. . . , Examine tho holo minutely with p. strong magnifying glass to see that it ia perfectly round and smooth; it not make it so. If unable to do this, throw the sheet away and start again. 1 Exercise some patience, as the success of tho picture depends on the "pm holo being of tho first quality. If working with a half-plato or a similar camera, in which the lens is removable. A special' pin. .hole lens may bo obtained at small cost. I have used ono with very great satisfaction, and, combining as it does, all sizes of holes and case for attachment to all sizes of cameras, leaves little to be desired. SEVEN RULES FOR PHOTOGRAPHERS. L—Keep tho dark room locked all 'times except when working therein. o,—Never drink from a graduated glass or other darkroom utensil. 3.—Do not keep a drinking tumbler in the dark room. .j,_—Never use kitchen or table utensils for dark room work. 5 —Never convey food to the mouth after working in the dark room unless tho hands have been thoroughly washed with soap and water. 6.—lf susceptible to metol, rodinal,' or potassium bichromate poisoning, never work with those chemicals except wearing rubber gloves. 7.—Wash tho hands with soap and water and dry on a clean toad immediately on leaving tho dark room. Tho above precautions are given by' Paul L. Anderson as being tho best way of avoiding accidental poisoning from photographic chemicals. Wo advise readers to cut tho rules out. paste them on a card, and fix in a prominent position in tho dark room.—'‘Photographic Dealer."