Army

PUBLISHED BY
THE ASSOCIATION OF THE U.S. ARMY

June 1969

Page 61- 65

Beginning in 1963 Camp Evans was the home of the Army Photo-Optics Laboratory. Thanks to Irv Bauman who provided this article and who directed the development of this equipment in building 9037.
Eagles' Eyes
For The Infantry From portable darkrooms and photo-interpretation vans to sophisticated aerial cameras, military photography is geared to provide the man on the ground with quick and precise images of his enemy.

by James H. Hoque, Assistant Editor

     Military photography has come a long way since Mathew Brady and his teams of photographers tramped over Civil War battlefields. Their cameras were crude compared to today's complex equipment, of course, but Brady and his assistants were the forerunners of a long line of combat photographers and among the first to use on the battlefield an instrument that today is a vital part of military science.
    The big spur for military use of the camera came in World War I with the introduction of the airplane. Military intelligence officers quickly discovered that aerial photos were the safest, fastest and most accurate means of gaining knowledge about the enemy, and they took thousands of photos each day.
     In World War Il, 80 percent of all intelligence was gathered through. aerial photos, a ratio, which continued in the Korean War,   Today, aerial reconnaissance is virtually indispensable to the fighting in Vietnam where there are no front lines and a unit may have to move into new territory on very short notice.
     The key to the aerial photo operation in Vietnam is the Mohawk reconnaissance plane which the Army has deployed there since 1963. Equipped with photographic equipment, radar, and infrared systems, the plane has proved its worth many times over, espe-

cially for airmobile operations.
     On the ground the plane is supported by self-contained mobile darkroom and photo interpretation vans in which technicians can process and interpret film quickly. There is usually a short delay between the time a commander requests a photo run on a particular area and the time the prints are in his hands.
     The Mohawk carries two cameras: the KA-30 which is mounted in the belly of the plane and takes vertical shots; and the KA-60, a panoramic camera mounted in the nose which takes in a 180-degree field of view.
     The output of both cameras can be highly useful. For instance, pilots who will have to fly into a landing zone on an airmobile operation can be provided with vertical photos that show the way the zone looked an hour ago, and oblique, 180-degrees-wide photos which show them how the area will look as they approach it.
     Both cameras are set up so that each picture frame of the film overlaps the preceding frame by 60 percent. This device provides a stereo effect in the final print and aids the photo interpreter in judging height and distance. The added realism also makes it much easier for pilots or infantrymen to get a feel for the terrain.

June 1969 ARMY 61

A 1st Cavalry Division (Airmobile) outpost in Vietnam as seen through the panoram

     Aerial photography has special problems that can be appreciated by anyone: whose hand has jerked just as he was snapping a picture with his Instamatic. Not only is the ground to be photographed moving faster than 200 miles an hour but the aircraft is also vibrating and in motion.
     To compensate for the relative movement of the aircraft, aerial cameras are adjusted to move the film along at the speed of the plane. This essential device, called "forward motion compensation," keeps the film stationary with respect to the object being photographed and ensures a clear image on the print.
     Considering the complexity of the photographic systems on the Mohawk it might be surprising to learn that the films used in these cameras are not basically very different from those used by amateurs.
     An exception is Kodak Ektachrome Infrared Aero film which is used to detect camouflaged objects. Called a "false-color" reversal film, its usefulness comes from the fact that the colors in the processed transparency have no relation to those of the original subject. The enemy may paint a large gun or bunker to look like surrounding trees and underbrush but he cannot camouflage its sensitivity to infrared radiation. Paint or metal absorbs infrared radiation while living plants reflect it quite strongly due to the pres-ence of chlorophyll. Color reversal film, which is sensitized to infrared radiation, will reveal this difference. When the infrared "false color" transparency is processed, the genuine foliage may appear, for instance, as pale blue. But the bunker or other camouflaged object will reveal itself as shocking pink.
     In tactical areas, film processing is usually done in portable developing vans. The ES-38 portable photo-

graphic darkroom, introduced to the field in 1964, is used to process all Army aerial imagery-optical, infrared and radar-that is not automatically processed in flight.
Weighing less than three tons, the van can be moved on short notice by truck or helicopter. It is completely self-contained except for electricity and can carry its own water supply.
The Army is looking for a new tactical imagery processing laboratory that will eventually replace the ES-38 but funds for development are, still pending.

Often deployed in conjunction with the ES-38 at division, corps and field army headquarters is the tactical image interpretation facility (AN/TSQ-43). This self-contained van houses equipment for interpreting intelligence information from photographic, radar and infrared sources. It represents a big step forward from World War II and the Korean War where photo interpreters often worked in poorly lit tents with simple stereo-viewer and dividers. The van can accommodate five image interpreters working with lighted plotting tables, stereoscopes, microscopes and a computerized viewer. It also has telephone, radio and teletype gear so that interpreters can report their findings immediately to the field.
A major drawback of current portable darkrooms is the amount of water they use. The ES-38, for instance, requires 300 gallons of water for every 12 hours of operation. In a tactical situation this much water may be difficult to obtain.
The problem is expected to be solved by the new ES-82A darkroom which is currently undergoing expedited testing. This mobile van for processing ground

62 ARMY June 1969

lens of a KA-60 camera mounted in the Molrawk reconnaissance plane

film will have facilities for a new "dry" process of film developing introduced by the Eastman Kodak Co., which requires only minute quantities of water and gives the user both developed negatives and positive transparencies.
     The Army agency charged with photographic research and development is the Electronics Command's Photo-Optics Laboratory at Fort Monmouth, N.J. Here, D. L. Castellini heads up a team of military and civilian scientists who seek to meet the Army's current needs and explore some of the farther-out reaches of photography.
     Much of the lab's work is directed toward improving camera systems already in use and testing new commercial products to see if they might be adapted to military uses.
For instance, gyro-controlled mounts used to stabilize the cameras are effective but they are also bulky and heavy. The lab is testing a possible sub-stitute called the Dynalens. Compact and relatively light, the Dynalens fits on the front of the camera and compensates for vibration and motion by deviating the light path through the camera to the film.
Conventional panoramic cameras provide a 180-degree field of view by means of a rotating prism and lens but the rotation also causes distortion in the image. To counter this problem, the lab is testing a new type of panoramic camera with stationary optics that exposes a 150-degree field of view simultaneously. It thus eliminates the distortion inherent in scan-type cameras.
     Many of the experimental cameras at the photo-optics lab are designed for use in helicopters. A compact 35-mm. panoramic camera called the Minipan

can be mounted externally on a helicopter. The Minipan gets around the necessity for a bulky stabilized mount by using high shutter speeds and a unique system of rotating folded mirror and lens.
     The lab has also developed a hand-held camera for helicopter reconnaissance. A 35-mm. single lens re-flex with a gyro mounted underneath for stability, the camera can be fitted with a Questar telescopic lens for long-range photos. Using this outfit, a crew-man can stand in the doorway of a helicopter in flight and still take a good picture.
      Larger camera system that has already been tested in Vietnam employs two Nikon 35-mm. cameras, one mounted above the other, and a stabilizing mount in which the cameraman sits. The upper camera is fitted with a 50-mm. lens and the lower has a 1,600-mm. Questar telescopic lens which magnifies 32 times. Using an auxiliary sight, the cameraman orients him-self to the target and then zeroes in with the tele-scopic lens for a detailed shot. The cameras are syn-chronized so that photos can be made simultaneously. When a photo interpreter later reads the prints he is better able to evaluate them with a general and a specific view of the object.
An important characteristic of these cameras is that they can be used by a person with a minimum of training in photography.
     An even simpler military camera, the KS-100, is currently being procured. This uses Polaroid film and produces black-and-white photographs in 15 seconds and color prints in 60 seconds. Simple to operate and rugged, the hand-held unit can be used from the door of a helicopter or on the ground.

June 1969 ARMY 63

The ES-38 portable darkroom is used to process all Army aerial imagery that is not automatically processed in flight.

     While much of the work at Fort Monmouth is concerned with camera and film hardware, scientists there are also engaged in experimental research.
     One area they have explored with considerable success is the processing of low contrast prints. This problem is familiar to anyone who has tried to snap a picture of a scene that includes an intense light source, such as a lamp. If the picture is printed to bring out the surrounding objects, the area around the lamp will appear much too bright. If the bright-ness of the lamp is reduced, then detail in the background will suffer.
     To counter this, scientists at the lab have invented a special developer that will reproduce a low-contrast print without loss of photographic speed. Since the negative is developed to a very low contrast, over-exposure is no problem. Even 1,000 times overexposure results in good negatives. In practice, this means that exposure meters and other such controls can be eliminated and the camera preset for the poorest lighting conditions likely to be encountered on a

Inside of the ES-82A, a portable dark-room for processing ground film that is currently being tested by the Army.

mission. Also, critical photos that have been badly exposed can be "saved."
Another process the lab is experimenting with is photoelectrolytic imaging, a whole new approach to photography that could make obsolete the silver halides now used in conventional film. In this process, an image is projected against a "sandwich consisting of a photoconductive layer in contact with an image-recording layer. When electric current is applied to the plate it becomes sensitized to the pro-

The Dynalens fits on the front of an aerial camera and compensates
for motion and vibration by deviating the light path to the film.

64 ARMY June 1969

jected image. The plate is then washed and dipped in black dye, which reproduces the image.
If perfected, photoelectrolytic imaging would simplify the photographic process by eliminating the negative-to-positive step, as well as ending the need for silver, an increasingly expensive commodity. More importantly for a military application, photoelectrolytic images are not sensitive to nuclear radiation, whereas conventional silver halide film is easily destroyed by such radiation.

     The most impressive research at the photo-optics lab is in the field of holography. A hologram is a photographic plate on which information has been recorded by reflecting laser light off an object. When the plate is developed and again subjected to laser illumination the image appears. Because the hologram affects the laser light waves in the same manner as the object does natural light, the reproduced image is three-dimensional.
     Viewing a hologram bathed in the deep ruby light of the laser is an exciting experience. The effect is exactly like looking through a window. All objects in the scene are very detailed and seem to be suspended in space. Moreover, as the viewer changes position the scene changes. One can literally look around the hologram just as he might look out a picture window, with objects coming into view or disappearing as the onlooker changes his viewpoint.
     The viewer immediately thinks of the potential for holograms in the movies or television and this application is being pursued in industrial laboratories. One of the problems with the hologram is that it is almost too realistic; that is, it reproduces much more information about a scene than can now be transmitted through the medium of television or motion pictures.
     The potential applications of holography to military intelligence are obvious. Equipped with a hologram of the terrain, a photo interpreter could easily

Many aerial cameras have been devised for helicopter use. The Minipan (left) is a panoramic camera that can be mounted externally on a helicopter. Above is a hand-held 35-mm. camera fitted with a Questar telescopic lens and a gyro mounted underneath for stability. Below, sitting in the counter-batanced mount of the dual camera system, a cameraman can take either conventional photos or long-range, shots with the lower camera which has a 1,600-mm. Quester telescopic lens.

measure heights and distances. He could view the hologram from different angles. Pilots who will have to fly into the area and commanders who will have to operate there would have a much more realistic picture of what it looks like than they could get from a conventional flat print.
     Such applications will not be perfected overnight but new processes like holography are sure to show the path to the future in photography and to the military they will add a whole new dimension in finding and attacking the enemy.
     Present intelligence photographs have proven their worth in Vietnam but the mind boggles at the potential effectiveness of a commander armed with a hologram of the enemy's camp. He will have an image so realistic he can almost get down and look inside their bunkers.
     Mathew Brady wouldn't have believed it.

June 1969 ARMY 65

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