apochromatic vs achromatic microscope
Semi-plan (semi-planar, sometimes called micro-plan) objectives have an 80% flat field. White light contains all the wavelengths and is known as polychromatic. Besides some special microscope objective lenses, there are three kinds of objective lenses which are achromatic, semi-plan, and plan. An object reflecting 700nm waves (and absorbing the others) appears red. Apochromats are the most expensive (and not by a small margin, either). Check the affiliate shop for microscopy-related products. This is a brand new 60X Achromatic microscope objective lens with high quality. The red components of the light are focused differently than the blue components. In such systems, the lens is placedbetween the objective lens, or a primary mirror and the eyepiece. A plan (or planar) objective corrects better for color and spherical aberration than either the semi-plan or the achromatic objective. Because of their high level of correction, apochromat objectives usually have, for a given magnification, higher numerical apertures than do achromats or fluorites. The links now work! Apochromatic objectives often have the designation APO written on them. For more information