PROCESS CAMERAS.

By J. ARTHUR H. HATT.

T is well known that process photographers have been severely handicapped for the want of a good camera, one which lends itself equally well for direct and indirect half-tone, and for two, three or four-color work. Especially is it necessary that the camera may be easily focussed to one hundredth of an inch, if desired. And this fine adjustment should be done with the turn of a screw, without having to spend from five to fifteen minutes in pushing the bulky camera itself to and fro. It is equally essential that the screen distance shall be easily regulated, and that the photographer can be sure that once regulated, the distance will remain exactly as he fixes it.

This feature of accuracy of adjustment is particularly necessary with the three-color half-tone photographer, who has to register his three negatives accurately whether the positives he has to work from are correctly in register or not.

Similarly, for direct work on dry plates, the utmost accuracy of adjustment between screen and plate is necessary, because the dry plate requires much less separation between screen and plate than the wet plate.

The front of the ideal process camera should be perfectly rigid, because a movable front cannot carry a heavy lens and prism and remain trustworthy, especially if these are adjusted to a cone. There should be a cone on such a camera: first, to supply the necessary angle of view, and secondly, to permit the change of color filters during the exposure of one plate. This is usually done by means of a dark slide in the

cone.

It is almost twenty years since I began my tussle with the great American process camera and some others made by other nations. In the beginning, as I freely confess, I did not know just what I did want in the way of a camera, and was satisfied to do the best I could with the apparatus I had.

My first half-tone work was done with a kit made by the late Mr. Wolfe, of Dayton, Ohio. The kit was arranged to hold a screen on one side and a wet plate on the other. They were not easily adjusted to different spacing between screen and plate. Another drawback this kit had was that one had to use a plate the size of the kit every time. Fancy making a single column negative on a 14 x 17 wet plate. On the whole, however, the kit was reliable and would remain, as far as separation is concerned, just as it was fixed.

The next contrivance I used consisted of a kit to hold the half-tone screen in front of the wet plate carrier. This was an improvement on the Wolfe kit in that it permitted the use of a plate smaller or larger than the half-tone screen. In accuracy of adjustment it was not as good as the Wolfe arrangement, but on the whole, more reliable than those in use. to-day.

About fourteen years ago I was the managing owner of the American Process Engraving Co., of Cincinnati, and had my first experience at that time with the adjustable holder. This utterly failed in its inability to keep the separation distance fixed as arranged in focusing. I therefore converted the camera for use in line work and took up a new French process camera made by Goring & Co. The screen adjustment of this camera was very accurate. The holder was made altogether out of machine finished iron. The screen was adjusted with a micrometer screw placed outside the camera, down at the bed. The drawbacks were its movable front and its great weight. It was only a 14 x 17 camera but it required two men to lift it. Another bad feature was the plate holder. This consisted of a nest of movable kits with glass corners. If the glass had a corner off it had to be discarded. This instrument was the first I worked with in which the screen was in the camera and not in the holder. For large plates this is a decided advantage. For small cameras from 14 x17 down, I believe that most process men would prefer to have the screen in the holder, for many reasons.

The latest process cameras made in America seem to be more or less copies of the Penrose camera, and for that reason we can consider them all at once.

The Penrose type of camera has a movable front, which is a

disadvantage for any work requiring accurate register. It has a screw for moving the front used in accurate focusing, which works admirably for all work in which a turned negative is used, but for direct work, or reverse negative work, it is obviously of no use for focusing, This type of camera cannot be made accurate enough for screen adjustment without using dry plates for the production of half-tone negatives. The moving device to place the screen in position before the plate cannot be relied on to place the screen accurately in position after the device has become a little worn in use. I have known this defect to be apparent even in new cameras of this type.

The dial usually found on the outside of this camera is also lacking in perfection. It is very much like picking the teeth with a crowbar to get the accurate measure of a screen adjustment to one hundredth of an inch on one of these dials. It does not always follow that if you see it on the dial it is so. The process photographer who has to do good work must have accurate adjustment and must be able to measure actual screen distance itself with a gauge. Some of the cameras of this type have curtain slides, which makes it still troublesome to get at the real distance to measure it.

It has been my opinion for some time that most of our process cameras have been designed by persons having but a superficial knowledge of the process photographer's needs.

Some time ago I took the time and trouble to design a practical camera which would fulfill all the requirements. My suggestions were offered to the various camera manufacturers but it has taken me a whole year to interest one of the lot in these suggestions. At last the Century Camera Co. has agreed to build a process camera according to my specifications.

If they do this, I can promise that the process photographer will be able to save half an hour to one hour every day simply in the adjustment of the screen. He will have a camera with which he can focus accurately by means of a screw for either direct or indirect (turned or reversed) negatives, and when the screen is once adjusted, it will remain so even if taken out of the camera and replaced. This will be of great advantage to the newspaper worker who has little time for adjustment; when his screens are once set he can change them as often as he likes and they will always be right. This camera will have

a cone with a dark slide, which will enable the photographer to place his color filter between the lens and change it during exposure, making two or more exposures on one plate through various filters. This will be especially useful in making the black negative in four-color work.

I am also in hopes that the new camera will have a glass trough as the bottom plate carrier, which should keep the silver away from the rest of the camera to some extent.