Small specimens necessarily require intense illumination, especially at high magnifications, and this is usually provided by a fibre-optic light source. Fiber optics utilize halogen lamps which provide high light output for a given power input. The lamps are small enough to be fitted easily near the microscope, although they often need cooling to ameliorate high temperatures from the bulb. The fibre-optic stalk gives the operator much freedom in choosing appropriate lighting conditions for the sample. The stalk is encased in a sheath that is easy to move and manipulate to any desired position. The stalk is normally unobtrusive when the lit end is near the specimen, so usually does not interfere with the image in the microscope. Examination of fracture surfaces frequently need oblique lighting so as to highlight surface features during fractography, and fibre-optic lights are ideal for this purpose. Several such light stalks can be used for the same specimen, so increasing the illumination yet further.
More recent developments in the lighting for dissecting microscopes include the use of high-power LEDs which are much more energy efficient than halogens and are able to produce a spectrum of colors of light, making them useful for fluorophore analysis of biological samples.