American cinematographer (Jan-Dec 1931)

by HAL HALL WE HAD hoped that Mr. Stull, who conducts this department, would be well and back at his desk in time to write for the March issue. However, such is not the case. Just as he began to feel somewhat like his old self he was stricken with appendicitis. At this writing he is on the road to recovery and asks us to send his best wishes to those who read his department each month. So, you will have to bear with me for another issue. At this particular season of the year, between winter and spring, many amateurs feel that there is little chance to use their 16 millimeter camera. They look through watery windows at the driving rains, at the cloudy skies or the bleak landscape. Then they long for the sunny days that are to come. Few realize that they are passing up the opportunity of making subjects that are unique and really worthwhile. There is nothing more interesting than a subject photographed in the rain. With the fast lenses of today, dark days are not what they once were to the photographer. In fact, untold possibilities are revealed, and from an artistic point of view the amateur may make a screen picture of much greater pictorial interest than in the summer days when the sun is blazing down and not a cloud is in the sky. The great banks of drifting clouds alone furnish pictorial attractiveness that one should not fail to take advantage of. Dark clouds, dripping rain, unusual reflections on wet pavements, distant landscapes veiled with a moody mistiness, light coming from a flatter angle, making it possible to secure artistic effects closer to the middle of the day than you can a month later — all aid the amateur in making pictures that will be little jewels in his collection. An interesting series of pictures for a serious amateur may be made during the four seasons of the year. Select a spot that lends itself to pictorial beauty. Photograph it in the middle of winter when the ice and snow covers all. As spring arrives with budding leaves and drenching rain, photograph it again. And then when summer is here and the entire scene has changed, photograph it in kodacolor. As the climax, again in kodacolor, photograph it in the autumn when it is bathed in the gorgeous colors of that season. If well thought out and intelligently photographed, you will have a picture you will be proud of, and which will challenge your cinematographic ability. While on the subject of rainy day photography, this writer has often wondered why the general run of amateurs puts the camera away on a rainy day. He may be making a trip around the world, and recording it on his film. But — if it rains when he is in Boston he usually makes no pictures. Why not? It seems to this writer that what you want is a photographic record of the trip. Why not make it in the rain if it is raining? Those may be the best pictures of the lot. A friend of mine recently showed me some pictures he had made while on a trip to Alaska. It rained a large part of the time he was there, and — the best pictures he had were those made on the rainy days. There was a certain air of mystery about the mountains with the mist and clouds that fairly made one gasp with delight. Why not try it? Filters The subject of filters seems to be a fly in the ointment to many amateurs, judging from the number of questions that reach this office. Many ask why they should use filters. Many ask how to use them. In the first place, color-filters are a means of correcting the discrepancies between the way the film sees colors, and the way our eyes see them. That is, the film sees colors according to one scale of brightness, and our eyes see the same colors with quite different degrees of brightness. If we arrange a strip of cardboard painted blue-violet at one end, and graduating through the entire spectrum to red at the other end, with yellow approximately at the middle, our eyes will register the middle section as being the brightest, with both ends shading off deeper and deeper. But if we photograph this same colored strip, we will have proof that the film sees color very differently from the way we do, for our picture will be brightest at the blue end, and then shade down to an almost dead black in the red section. This is because the blue light (and, beyond it, the invisible ultra-violet) is the most active photographically, while the red is almost inert. Therefore, if we want to get anything like a true rendition of the colorvalues our eyes see, we must in some way hold back a portion of the powerful blue rays, and give the weaker greens, yellows, and reds a chance to make their impressions upon the film. That is what light-filters are for. The better grades are so made that they not only retard the blue rays, but quite absorb the invisible ultraviolet frequencies. But, in order to work under all conditions, we must have a variety of filters: some that hold back only a little of the blue, and some that hold back a great deal of it. Therefore filters are made in several grades, the light-colored ones holding back only a moderate part of the blue, while the darker ones retard more and more of it. However, no commercial filters hold back all of the blue rays, for that would be as serious an exaggeration in its way as the original condition the filter is intended to correct is. Now, when these filters are used, it will be seen that they are removing a pcrfion of the light (and the most active portion, at that), but they are not adding anything to take its place. Therefore, in order to keep the exposure correct, a longer time must be given, or a larger amount of light allowed to work on the plate: and this increase must be directly proportioned to the amount of blue light cut out by the filter. In amateur movie work, where the time of exposure is usually fixed, this compensation must be made by opening the diaphragm on the lens. In order to make this compensation accurately and conveniently, the manufacturers have determined what is known as the "filter factor" for each of their various filters. There are so many different makes of filters on ths market today that it would be impossible to give here the factors of anything like a comprehensive number of them; however, among the most popular ones are the "Wratten" K series made by the Eastman Company, and of these the ones most used in amateur movie-making are the K 1, the K 1 V2, and the K 2. The lightest of these, the K 1, absorbs 60r.of the blue rays, and passes nearly 80 % of all the others; its (Continued on Page 35) 30