Meiji Techno, MT5310EL/LBC, Advanced Live Blood Cell LED Ergonomic Trinocular Brightfield/Phase Contrast Biological MicroscopeMT5310EL/LBC Includes Only:Computer Aided DesignErgonomically positioned controlsComfortable Siedentopf viewing headsYour choice and preference in illumination, halogen or LEDBrightfield, darkfield and phase contrast observation modesAccessible with motorized stage and focus driveOptional Ergonomic Binocular Viewing Head AccessiblePhase Contrast optical components needs to be aligned to the condenser annulus with the phase plate in the objective rear focal plane with a phase telescope, that inserts into one of the microscope eyepiece observation ports. The phase contrast annulus is used in the substage condenser on Meiji Techno's upright microscope within the condenser turret.  The Phase ring in the condenser must be specifically matched to the particular Phase objective equipped with a corresponding phase plate annulus.  For example, the Phase 10X and Phase 20X both of which contain a phase plate will require a condenser annuli having different diameters that correspond to the objective magnification and N.A. (Numerical Aperture). By properly matching the Meiji Techno Condenser annulus to the objective phase plate, the Meiji Techno Phase microscope can be aligned to superimpose illuminating light rays passed through the annulus onto the Phase ring of the objective to achieve proper Phase contrast illumination.The Ph1 condenser annulus , which contains the smallest aperture, is designed to be used with the lower power 10X and 20X Phase objective. Intermediate magnification objective  40X Phase utilize the Ph 2 annulus, while the highest power and N.A. 100X objective require the Ph 3 annulus, which requires the largest phase annulus.