The principles involved in the construction of a skylight for commercial purposes such as photographing furniture and other manufactured products are necessarily somewhat different than for a skylight designed especially for a portrait studio.In commercial work the problem is to secure an even distribution of light and to avoid extreme contrasts. The degree of roundness and brilliancy which is sought in portraiture would be entirely unsatisfactory to the manufacturers of various articles which are sold largely from photographs.
Such photographs not only require brilliancy but also a more even distribution of light to pick up and register every detail ranging from the most extreme highlight to the deepest shadow. This might convey the idea that flatness is wanted, but as such photographs would not be interesting, this is to be avoided.
The problem then is to secure a soft, even illumination and also to preserve brilliancy. To secure uniform illumination, it is almost necessary to have the light come your friends can buy anything you can give them - except your photograph.
There's a photographer in your town. Eastman Kodak Company, Rochester, N. Y. from practically all directions at once. However, the illumination must be under perfect control and, even though not apparent to the eye, a little stronger from one direction. In the accompanying diagrams we have illustrated a skylight which is very suitable for the general requirements of the average commercial photographer.
On the north side there is a plain glass side light starting at about one foot from the floor and extending vertically eight feet from the floor. This light for an operating room forty feet long should be about fourteen feet wide. Plain glass would be suitable for the north side light as it never receives the direct sunlight. The top light should preferably be built of heavy corrugated glass. It is advisable to have the top light built as flat as practicable and it should extend pretty well across the room. The top light should be built flat enough to bring the extreme height at the peak at about fourteen feet from the floor.
ARTURA PRINT FROM DEMONSTRATORS NEGATIVE
On the south side a smaller light constructed of ground glass should extend to a height of about ten feet. The width of this south light need not be over eight feet. It is advisable to have the north side and top lights start at about six feet from the west wall, which brings the eastern edge of the light to the middle of the room. The south light should start at about twelve feet from the west wall and should also extend to the middle of the room so that the eastern edges of both the north and south lights are directly opposite.
With lights of this construction and with complete sets of white muslin curtains, it is possible to secure perfect light control and to obtain uniform and evenly illuminated negatives under all conditions of weather. By drawing the top and south curtains to exclude the sun on bright days, and by using the light wide open on dull days, comparatively uniform exposures may be obtained. A soft light and full timing is an important factor in obtaining negatives of the desired quality in commercial photography.
The plans suggested are suitable for an operating room twenty feet wide by forty feet long. This would be a very suitable size for the average commercial studio. If, however, this amount of space is not available, a room of somewhat smaller dimensions may be successfully used, but in such case the size of the skylight should not be reduced in proportion to the size of the room. It may be made smaller but must have sufficient size to properly illuminate any object that is to be photographed.
ARTURA PRINT FROM DEMONSTRATORS NEGATIVE
It is possible to do without a Stirring Rod, but the use of one certainly saves time and insures proper mixing of your chemical solutions. The ordinary wooden rod is open to objection, because it soon becomes water-logged and soaked with chemicals. The most efficient is the Thermometer Stirring Rod, which combines the functions of a thermometer and a stirring rod in convenient form. Your stock house sells these at 60 cents each.
For a stirring rod, pure and simple, there's nothing better than the Eastman Hard Rubber Stirring Rod, which will last indefinitely, because it is made of hard rubber, moulded around a core of aluminum - acid-proof and break-proof, as well as non-absorbent. Your stock house sells these at 20 cents each.
Another handy device that will last for years and years is the Eastman Hard Rubber Print Paddle, which is made on the same principle as the Stirring Rod. You can sure enough whittle out a print paddle in a few minutes, but you've got to keep on whittling them out, whereas a paddle of hard rubber does not become useless through soaking up chemicals, etc. Besides, the shape of the paddle is ideal for separating prints, and your hands need never be put in the Hypo, if you use one of these paddles. Price, 35 cents each, at your dealer's.
It's a good scheme to have on hand a series of Masks for prints of various sizes that will all fit the same frame, but paper masks are hardly durable enough. The thing to use for making up such a series of masks is Eastman Masking Blanks, which may be had at $2.00 per dozen to fit an 8 x 10 frame. They are made of tinted film support, medium weight, and the transparency of the mask makes it a simple matter to secure perfect registration of paper and negative. Of course, you can cut masks of any dimensions you may desire.