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HOW THESE IMAGES ARE CREATED
The development of these images takes place in a multi-stage process, in which most of the procedures are often quite intensive. Samples are first prepared for placement in the scanning electron microscope (SEM) in any number of ways depending on their size, composition, hydration state, and type of desired results (images, chemical analysis, etc.). They must typically be rendered electrically conductive by sputtering or evaporating a thin layer of carbon or a metal such as platinum over their surfaces. If moist or wet, they usually first undergo a lengthy dehydration procedure called critical point drying.
Once inside the SEM's sample chamber, an electron beam of chosen voltage is projected down through a stack of electromagnetic lenses onto the specimen below. Electrons from the beam that strike the sample and scatter back up again are collected by a specialized detector that yields an image of the sample's surface whose gray levels correspond to areas of differing chemical composition. Electrons ejected from the sample's own surface by the beam's impact are converted by a second specialized detector into a remarkably crisp, three-dimensional image of the sample's texture or structure. This type of image is the one most commonly associated with the SEM.
The imaging process normally takes place under vacuum. Physically inaccessible inside the chamber, the samples can be explored in detail through the use of external controls that can rotate, tilt, and move them up, down, and sideways. The sample's image is viewed on a monitor as other controls are used to zoom in and out of chosen areas in order to view them at higher or lower magnifications. Any image seen during this process can be recorded at will. Electrons can't convey color, so electron images are always produced monochromatically and then photographed either digitally or on film. If film, they are subsequently hand printed and scanned to digital format. The final stage in the creation of enhanced micrographic images such as these, is "cleaning" and colorizing, when desired, using Adobe Photoshop software.
It takes three or four days to create each image but the individual stages often take place over many years, particularly with time separations between sample collection, raw micrograph capture, and post-processing. Except in cases where scientists have collected specific research samples, Dee conducts the entire process from sample collection and preparation through to post-processing. Each image can be supplied either monochromatically or colorized, often in several versions, and occasionally in both positive and inverted versions. They can also be custom colorized on request. Custom microscopy of a desired sample can be arranged as well.
© 2006 Dee Breger