When a person is using a microscope is it very important to use the proper lighting. Each specimen is different and some need to be looked at with different shades of light. When using a conventional light microscope, light is used is aimed upwards at the lens. This light is underneath the condenser. The person using the light can see things that other microscopes can't because of the pigmentation that is natural. They will also be able to see things not normally seen because of the thickness of the stain that is usually colourless. The light helps to absorb the thickness. Many times, living bacteria will not show up at all. It will only show up by using maximum contract of light. The knob that is on microscopes will help to adjust the lighting to see various stains on the slides. Using the light microscopes will show up very small objects that can't be seen with other types of microscopes. Lighted microscopes are a very important tool in research labs, schools, etc.