OPTIKA MICROSCOPES B-500DK Manual De Instrucciones página 7

3.0 PRINCIPLES OF DARKFIELD ILLUMINATION
Figure 3 Cardiod darkfield condenser
Ideal candidates for darkfield illumination include minute living aquatic organisms, diatoms, small in-
sects, bone, fibers, hair, unstained bacteria, yeast, and protozoa. Non-biological specimens include
mineral and chemical crystals, colloidal particles, dust-count specimens, and thin sections of poly-
mers and ceramics containing small inclusions, porosity differences, or refractive index gradients.
Care should be taken when preparing specimens for darkfield microscopy because features that
lie above and below the plane of focus can also scatter light and contribute to image degradation.
Specimen thickness and microscope slide thickness are also very important and, in general, a thin
specimen is desirable to eliminate the possibility of diffraction artifacts that can interfere with image
formation.
Page 7