As an acknowledged expert in the field of photomicrography, Wilson Bentley had occasion to write many articles detailing the more technical aspects of his photographic process.
In a piece for American Photography, Bentley described his equipment:
The apparatus used in this work consists of the ordinary combination of camera and microscope, called a photomicroscopic camera, the lenses used being microscope objectives of ½-inch, ¾-inch and 3 inch, giving magnifications of from 8 to 60 diameters (64 to 3600 times). Ordinary daylight, entering through a small aperture (1/2 of an inch in diameter) in substage is used for illumination, the light coming through a window toward which the lenses and camera are pointed. – Bentley, W.A. (1922). Photographing snow crystals. American Photography, 16 (Jan-Dec, 1922), 10-12.
While noting that photomicrographic work did not require expensive equipment, Bentley did stress the need to guard against unwanted reflections, and to use extra care while performing final focusing.
In another article, Bentley wrote of the necessity for a very small stop (lens opening), reporting that one of 1/14 or 1/12 inch was best. He warned that a larger stop, admitting a greater amount of light, impaired both the definition and contrast between the light and dark sections of the crystal. The larger stop also made precise focusing more critical and more difficult. Photographic exposures ranged from 8 to 140 seconds, depending upon the intensity of the natural light and the amount of magnification. Quite obviously, the need to work quickly, in the cold, with such delicate precision, required considerable practice and skill.
In 1922, while preparing an article for The Vermonter, Lillian Loveland had the opportunity to meet and interview Wilson Bentley. Bentley led her into and through his three-room residence, past the cameras, books, boxes, and photos that were strewn about. Despite the disorder, Bentley apparently had some sort of system as he was able to retrieve photos and articles at a moment’s notice. Bentley showed Loveland the same old camera that he had used for all of his work, and also the various apparatus that he had invented to enable him to use it for both his photomicrographic and ordinary photographic projects. Loveland recounted Bentley’s process:
It is indeed a delicate task to “catch” one’s snowflake and get it in position to be photographed. Mr. Bentley has a tray consisting of a board painted black with wire handles on either end, on which he collects the flakes: this he carries carefully by the handles with mittened hands, in order to keep off all animal heat: and to keep his hands warm too, no doubt: into his cold, unheated workroom. With a splint of wood, he painstakingly picks up the snowflake and places it on the slide of his microscope, being particularly careful that it is unbroken and perfectly flat so that all parts reflect the light equally.
“It takes me quite awhile sometimes,” Mr. Bentley explained, “and I have to breathe occasionally, but I turn my face away, take a quick breath and get to work again before the flake melts,” illustrating with a quick birdlike movement of the head.
“It must take a steady hand and infinite patience to manipulate those snowflakes,” I (Loveland) remarked.
“Yes it does. My hand is pretty steady though I have never used liquor or tobacco in any form. I don’t know as it takes so much patience: I like to do it.” – Loveland, L.S. (1922). Bentley, the “Snow Crystal Man”. The Vermonter, 27(11), 272-274.
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