This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
666. That a high-grade lens is a great addition to any-photographic worker's outfit is beyond question. It is not the purpose of this chapter to discourage anyone's ambition to some day become the proud owner of an "anastigmat." It is possible, however, to make photographs of unquestionable quality without employing a lens at all; and with but three exceptions, produce negatives equal to those secured with an optical instrument.
667. The pin-hole, as a substitute for the lens, possesses the undoubted merit of cheapness. For experiments it is possible to stretch a piece of black paper, from a spool of roll film, across the opening of an extra lens board, and with the hot point of a needle burn a tiny hole in the center. This hole may then be enlarged to the full diameter of the needle by gradually working the needle into it, rotating it between the finger and thumb in drill fashion. The cost of material is limited to one needle and five minutes' time - the cost of the black paper need not be taken into consideration, as it is a by-product.
668. The use of a pin-hole requires many times the amount of exposure to that of a lens. It must be borne in mind that the diaphragm value is almost the same, however, as if this same small opening were used on the lens. But, owing to the fact that there is no glass to retard the rays of light and cause cross reflections, a quicker exposure is possible than if the same size opening were employed when using a lens.
669. The most minute pin-hole will give a remarkably sharp image. As the size of the hole is increased the brilliancy fades, the image becomes "fuzzy," until, when the opening has been increased to quarter of an inch in diameter, there will be no recognizable image. Here is where the lens scores its strongest point. The optician can grind the glass and combine the various forms of lens cells to control the rays of light, making it possible to employ a large opening, and to produce a sharp image by admitting a great number of light rays instead of only a few, as is the case when working with the pin-hole.
670. It is a well-known fact that the larger the opening of the lens the less is the depth of focus. When a large opening is used the ground-glass cannot be moved as far forward and backward, without a single object becoming unsharp, as when employing a small opening or diaphragm. When a very small diaphragm is used almost the whole field covered by the lens (objects in the extreme distance and those within a few feet of the camera) is sharp. When using the pin-hole no object is out of focus (unsharp).
671. It is not possible to photograph moving objects when working with a pin-hole. At first thought, it might seem equally impossible to make a view of a busy street, or to secure a good landscape negative when the wind is blowing. It is right here, however, that the pin-hole will accomplish results that can seldom be obtained with a lens. For street photography the pin-hole has many advantages, but for the present it is sufficient to say that after having given from two to five minutes' exposure only those objects that have remained perfectly still during this time will have made any visible impression upon the sensitive plate. The people, cars, teams, carriages, automobiles, etc., which have been moving around in the meantime will not only leave no outline, but there will be no blur caused by them. The developed negative will show the buildings and all stationary objects in perfect form, while the moving objects will have entirely disappeared. When wind causes a movement of the trees in a landscape scene, the point at which the branches remain the longest time will produce the image and there will be no blur.
NEEDLE-HOLE LANDSCAPE Study No. 46 - See Page 315 By G. H. Paine.
OCTOBER DAY (PINHOLE) Study No. 47 - See Page 315 By C. F. Clark.
672. The three exceptions referred to in the first paragraph of this chapter having now been explained, they may be briefly summarized as follows: First, as the pin-hole requires from 60 to 100 times the amount of exposure of the average lens, it is impossible to use the pin-hole when one's time is valuable and when a hasty exposure must be made. Second, the definition is very uniform throughout the picture, for all objects, whether near or distant, are equally lacking in perfect definition. A general criticism, passed by artists, is that this definition is too uniform. Third, owing to length of the exposure it is impossible to photograph moving objects.
673. Though the pin-hole is of somewhat limited application, it should certainly be tried by the pictorial worker for certain effects, and it will prove useful to the technician for securing extremely wide-angled views in restricted positions.
674. A pin-hole has no focus - it may be placed at practically any distance from the lens - all that is necessary is to rack the camera until the desired angle of view is reached. It is necessary, however, to select a pin-hole of a size suitable to the camera extension. The greater the distance from the pin-hole to the plate the larger may be the pin-hole. If the distance is sixteen inches, the pin-hole should be about 1-12 of an inch in diameter. At a distance of ten inches, a hole l-40th of an inch is correct; while for six inches, the pin-hole may be l-50th of an inch. These sizes and distances are quite correct for the best definition, and are proper no matter what size of plate is employed. In order that these diameters may be accurately judged, various sizes of needles are employed. These are gauged by the needle manufacturers and the sizes are standard. Although the hole is made with a needle instead of a pin, the method is known as pin-hole photography, and it will probably continue to be known by this name.