The more we see the results of negative making with films which are sensitive to color and filters which aid in securing the greatest value from this sensitiveness of the film to color, the more are we impressed with the practical advantages of these materials and the ease with which they may be used even by the inexperienced.

Ordinary plates or films are called color-blind because colors other than blue have no practical photographic effect upon them. So it is not practical to use such materials to photograph an object containing several colors because the result is not at all as the object appears when we look at it. The photograph is not a truthful reproduction.

With orthochromatic films or plates which are sensitive to yellow and green as well as blue, very much better results can be secured, especially in landscapes, because there is a great deal of yellow, green, and blue in nature. But as orthochromatic materials can not be made as sensitive to yellow and green as to blue, it is necessary to use a yellow filter over the lens. This filter reduces the blue light so that the yellows, greens and blues will photograph in their correct relation to one another. Without a filter the blues would be over-exposed, or too light, while the yellows and greens would be under-exposed, or too dark.

The use of the filter must, of necessity, increase the exposure, and this increase depends upon how much blue light is cut out or absorbed. But as a correct type of yellow filter only cuts out blue light and in no way retards the action of the yellow or green, it is easily seen that there is no other way in which a result can be secured which allows of a satisfactory photographic rendering of green and yellow along with blue.

The yellow filters, Kl and K2, differ only in depth of color, the K2 cutting out considerably more blue light, requiring more exposure than the Kl and permitting yellows and greens to photograph considerably lighter in comparison with blue. As a result, with a K filter, yellow and green foliage in a landscape will photograph lighter than a blue sky and white clouds will show in excellent contrast against the darker blue sky.

But orthochromatic films and plates have decided limitations. They are not at all sensitive to red and can not correctly render reds or those colors which contain red.

PORTRAIT FILM NEGATIVE, VITAVA PRINT

By Charles L. Peck Buffalo. N. Y.

Panchromatic Films and Plates, however, are not only extremely sensitive to red but are also more sensitive to green and yellow. Their greater sensitiveness to these colors makes them proportionately less sensitive to blue and when used with yellow filters the time necessary for making exposures is considerably less than when the same filters are used on orthochromatic films or plates.

It is certainly not difficult to understand these characteristics of material which is color sensitive, but unfortunately some of the more technical literature on the subject has seemed confusing because the terms of the scientists have not always been familiar ones. As a result the photographing of colored objects with filters and Panchromatic Films or Plates has seemed difficult when it is not.

When you must photograph objects which are red or contain a considerable amount of red, as well as other colors, the red photographs the same as black unless a Panchromatic Film or Plate is used.

Red does not look as dark as black, in fact some shades of red appear much lighter than similar shades of blue or green because red is a bright color. It is vivid and produces a strong sensation on the eye. It is warm and cheerful but it ordinarily photographs dark and sombre and lifeless.

The photograph of the object containing red is not pleasing or truthful unless the red photographs as light as it looks. And it will do this if a Panchromatic Film and K3 Filter is used.

The K3 Filter appears to be much the same as the yellow K2, but it has the property of bringing all colors in their correct relation to one another so that they photograph only as dark or as light as they appear to the eye. The K3 is the proper filter to use with Panchromatic Film when you wish to photograph an object containing a great number of colors such as will be found in some rugs or carpets or upholstery or in an interior containing a great variety of color.

There are many individual cases, however, in which you need to show a decided difference between two colors that photograph alike. A label on a can of tomatoes, for example, may show a red tomato against a green background and the red is just as dark as the green.

We say that this label has good color contrast but when you photograph it on a Panchromatic Film with a K3 Filter one color photographs just as dark as the other, which is really correct, but is not satisfactory.

In the photograph there is no contrast of color so one of the colors must be made to photograph lighter than the other. For this purpose a contrast filter must be used. The contrast filters are dark yellow, green, and light and dark red. These filters make yellows, greens and reds photograph lighter than they appear to the eye.

PORTRAIT FILM NEGATIVE, VITAVA PRINT

By Charles L. Peck Buffalo, N. Y.

In the example of the red tomato against the green background the red (A) filter will make the tomato photograph lighter than the green background, while the green (B) filter will make the background light and the tomato dark. The dark yellow filter (G) will make yellows photograph lighter than they appear - in fact. yellow stains on a copy can be entirely eliminated by using the G filter.

There are two shades of red filters, the light red (A) and the deeper red (F), both of which are useful, though the F usually makes bright red photograph almost the same as white.

The use for these filters is readily seen and there is nothing complicated about their action. Exposure varies with the filter but a card packed in each box of Panchromatic Films or Plates gives the factor for each filter. If the factor for the K3 Filter is 3 you should estimate your exposure without the filter and give 3 times as much exposure when the filter is used.

The time of development is also given for various temperatures (0.5° being preferable) so there can be no difficulty about developing in the dark or in a covered tank for a definite time. Of course it is not possible to use a red light with films sensitive to red, but if a light must be used, a green Safe-light Series 3 will be found amply safe.

If you have never used Panchromatic Films and Filters, try them. Results are so wonderful that you will find yourself hunting for difficult subjects rather than avoiding them, and the solution of a difficult problem will often bring you profitable new business.

Keep Up Your Lines Of Communication

An army never gets too busy fighting to keep up its lines of communication. If it did it would soon find itself without the means to continue fighting.

You should never be too busy to give some attention to your display case even in the midst of the Christmas season. The display case is one of your important lines of communication with the public and an inexpensive one. But it is a mighty expensive one if you neglect it.

You are busy now, to be sure, but a great many people who see your display case are not having photographs made for Christmas. They may, however, receive photographs of friends at Christinas time and if so may be prospective patrons of your studio just after the holiday rush is over.

PORTRAIT FILM NEGATIVE, VITAVA PRINT

By Charles L. Peck Buffalo, N. Y.

Possibly your display is a bit stale just now because you have been too busy to change it. And if stale it is not attracting these people.Of course you must take care of present business - that is your greatest obligation. But when business is good, advertise for the season when it will not be so good. If you can't find time to change that display yourself, get someone to do it for you.