olympus-micro-optics奥林巴斯短桶物镜手册.pdfVIP

Oly,mpus Htgh Quality O Ptles OBJECTIVES Generally speaking, microscope objectives are divided into The curve 8 represents the optical characteristics of the various types according to their optical performance and ap- fluorite. The chromatic aberration of a fluorite is considen.- plicative. From the stand point of optical performances, such bly smaller throughout the entire spectrum compared to the as numerical aperture (N.A.), and corrections of various aber· achromat (curve ·A). rations. the Olympus objectives are divided into three types - achromats. fluorites and apochromats. The performance of .APOCHROMATS an objective basically depends upon its resolving power. This Objectives corrected chromatically for three colors and - resolving power is influenced by the N.A. and several aberra- spherically for three colors. These corrections are superior to tions. An increase in N.A. usually results in an increase of those of the achromatic series of objectives. Curve e in these aberrations. In designing an objective, one of the big- Fig. 1 shows the relationship between wavelength and chro- gest deterrents to an increase of the resolving power of the matic aberration of the apochromal, while Fig. 2 represents objective is chromatic aberration. Depending on the degree the differences in focal points of four given wavelengths (Red, of correction of this aberration, three main types of objec- Yellow, Blue and Violet) of an achromat (left curves) and an tives are obtained. They are called achromats, fluorites (semi- apochromat (right curves). The curves clearly-show the supe- apochromats) and apochromats.