Photography, in one form or another, has become so inseparably connected with almost every field of human endeavor that no one man can successfully master every phase of photographic work. There must be specialists but, as a rule, these specialists have taken up photography because they were compelled to do so. The physician became an X-Ray specialist because it was easier for him to master X-Ray photography than for the photographer to master the necessary knowledge of medicine or surgery.

And the same holds true in the application of photography to many branches of science. But it is also true that the commercial photographer is constantly broadening his knowledge and is becoming more nearly a technical than a commercial photographer.

Portrait Film Negative, Artura Print By M. B. Nicholson Kansus,is City, Mo.

Portrait Film Negative, Artura Print By M. B. Nicholson Kansus,is City, Mo.

Portrait Film Negative, Artura Print By M. B. Nicholson Kansas City, Mo.

Portrait Film Negative, Artura Print By M. B. Nicholson Kansas City, Mo.

Ferrite and Pearlite in Steel Magnified 1500 diameters.

Ferrite and Pearlite in Steel Magnified 1500 diameters.

There is much technical photographic work that can be done better by the photographer in co-operation with the technician than by either working alone. This is especially true when applied to photomicrography.

When a big gun, a sky scraper, a steel bridge or a powerful engine is to be built, the entire structure will be no stronger than its weakest part. The constitution and structure of the metals used must be known. Under the microscope the flaws are seen and photography records them.

More and more the element of chance is being eliminated. The engineer must know the structure of the metal he uses and depends upon the microscope for his tests just as the physician depends upon the report of the bacteriologist for his diagnosis of a diseased body, and both prefer photographic evidence.

The microscopist is not always a photographer, and the photographer is seldom a microscopist, but if he has a trend towards technical work he can soon master enough of the subject to make satisfactory photomicrographs either of transparent or opaque subjects. The amount of this work which the technical photographer might find to do would determine whether or not he would own a complete outfit or work with the microscopist and furnish only the necessary photographic knowledge and apparatus.

Plant Fiber Paper   175 diameters.

Plant Fiber Paper - 175 diameters.

Flax Paper   175 diameters.

Flax Paper - 175 diameters.

Brown Wrapping Paper 175 diameters Cross Section Photomicrographs.

Brown Wrapping Paper-175 diameters Cross Section Photomicrographs.

Portrait Film Negative, Artura Print By M. B. Nicholson Kansas City, Mo.

Portrait Film Negative, Artura Print By M. B. Nicholson Kansas City, Mo.

Thin Stock Photographic Paper.

Thin Stock Photographic Paper.

1 Silver Deposit, 2 Sub-stratum, 3 Paper Stock - 175 diameters.

Heavy Photographic Paper.

Heavy Photographic Paper.

1 Emulsion layer fixed out, 2 Sub-stratum of Baryta, 8 Paper stock - 175 diameters.

The apparatus for photomicrography consists of a source of light, condensing system, microscope and camera, all of which should be rigidly connected together so that the slightest vibration will affect every part of the apparatus in the same degree. Also, the apparatus should be capable of being fixed accurately in a straight line. Elaborate apparatus is not necessary if these requirements are fulfilled, but if much work is to be done, a piece of apparatus known as an optical bench is almost essential. This is a heavily constructed bed to which the instruments may be attached and on which adjustments can be made with accuracy.

Of the microscopes themselves little need be said except that only a first class instrument is really suitable for photomicrography. A suitable light source is a part of the equipment and is usually listed with it.

The objective lens of a microscope gives the initial magnification. The eyepiece, in turn, magnifies the original image. If the initial magnification is 40 and an eyepiece of 10 is used, the result will be a 400 times magnification on the ground glass of the camera when it is ten inches from the eyepiece. If the camera extension is twenty inches the magnification will be twice as great. And negatives may be made without an eyepiece or with eyepieces which give different magnifications.

Filters play an important part in the contrast of specimens photographed when colors are involved, the background of transparent specimens affects contrast and it is often necessary to line the inside of a microscope tube with black velvet to eliminate reflections.

If it is found that an ordinary camera can be attached to the optical bench and held sufficiently rigid, the lens is removed and the camera so adjusted that the eyepiece of the microscope projects inside the lens barrel, occupying about the same position as the camera lens which has been removed. Extraneous light, of course, must be excluded. The ground glass of the camera should have a three-quarter inch circular cover glass cemented to the center of the ground glass side with Canada Balsam, a pencil cross having been made on the ground glass before cementing. This enables one to do fine focusing with a magnifier.

There are detailed instructions for centering the image and focusing but these are only of interest to one actually engaged in the work. The main difference between the photomicrography of transparent and opaque materials is in the method of illumination, a specimen of a metal requiring vertical illumination, since the photograph is made by reflected light, while the transparent specimen is photographed by transmitted light, the lighting arrangement being varied accordingly.

We might go into lengthy details of the various steps in the work, but the purpose of this article is merely to give a general idea of photomicrography and its importance to the technical worker. Details of the subject would be of little interest to any but those who have taken up the work, or seriously contemplate doing so. The booklet "Photomicrography" covers the subject, giving much detailed information, and will be mailed on request to Microscopists, Photo-micrographers or technical photographers who contemplate doing such work.

Portrait Film Negative, Artura Print By M. B. Nicholson Kansas City, Mo.

Portrait Film Negative, Artura Print By M. B. Nicholson Kansas City, Mo.

Photomicrography StudioLightMagazine1919 175Portrait Film Negative, Artura Print By J. L. Rivkin Tulsa, Okla.

Portrait Film Negative, Artura Print By J. L. Rivkin Tulsa, Okla.