CMOS image sensors are designed with the ability to integrate a number of processing and control functions, which lie beyond the primary task of photon collection, directly onto the sensor integrated circuit.
When imaging specimens in the optical microscope, differences in intensity and/or color create image contrast, which allows individual features and details of the specimen to become visible. Contrast is defined as the difference in light intensity between the image and the adjacent background relative to the overall background intensity. In general, a minimum contrast value of 0.02 (2 percent) is needed by the human eye to distinguish differences between the image and its background.
Upon walking into a busy laboratory it isn't unusual to see microscopes sitting on books, tilted at odd angles, and otherwise precariously supported in a variety of positions to accommodate their users.