Filter Control of Specimen Contrast in Black and White Photomicrography

This tutorial explores the use of Kodak Wratten color filters for contrast control in black and white photomicrography when using stained specimens. Instructions for operation of the tutorial appear below the applet window.

To enhance contrast, color filters are added to the microscope light path to absorb stained specimen color, rendering it either a darker or lighter shade of gray. Contrast can be adjusted in this manner by selectively choosing filters that absorb varying amounts of stain color. The images presented in this tutorial can be used to explore these effects. Use the Choose a Specimen pull-down menu to select a stained specimen from the list. After selecting a specimen, use the radio buttons to simulate how black and white photomicrographs will appear when using one of three Kodak Wratten color filters: 25 (red), 58 (green), and 47B (blue). When a filter radio button is selected, the image changes to a black and white photomicrograph showing the results of the filter selection. Use the three filter algorithms, either individually or in groups, to view how filter combinations can use used to adjust contrast in black and white photomicrography.