Achromatic objectives

The least expensive (and most common) objectives are the achromatic objectives that are designed to limit the effects of chromatic and spherical aberration. Achromatic objectives are corrected to bring two wavelengths of light (typically red and blue) into focus in the same plane. The limited correction of achromatic objectives leads to problems with color microscopy and photomicrography. 

Apochromat Microscope objective that has better color correction than the much more common achromat objectives corrected chromatically for two wavelengths of light (red and blue). Apochromatic objectives are corrected chromatically for three colors (red, green and blue) and spherically for two colors, which practically eliminates chromatic aberration. 

Neofluar objectives are chromatically better corrected than the achromatic objectives (fluorite), but worse than the plan-apochromat objectives. The contrast of the neofluar objectives is however larger than with the plan-apochromat objectives. 

Colorant A substance, such as a dye or pigment, that modifies the color of objects or imparts color to otherwise achromatic objects. 

The intrinsic images obtained by the method of Finlayson and Hordley (2001 a,b) only depend on the reflectance of the object points provided the illuminant can be approximated by a black-body radiator. Since a green illuminant cannot be approximated by a black-body radiator, the result will not be an intrinsic image. That aside, here, achromatic patches are illuminated by four different illuminants. Finlayson et al. compute the logarithm for each channel and subtract the geometric mean. The resulting coordinates are denoted by p, for i e [r, g, b ... 

UV microscopes are supplied mainly by two optical companies, Zeiss and Leitz, in the Federal Republic of Germany. The major difference between the Zeiss and the Leitz instruments lies in their optical systems. The Leitz microscope uses quartz refleeting objectives, while Zeiss uses quartz refractive objectives. Both objectives are achromatic for a wide portion of the UV and visible light range, with no shift in focus accompanying the change of wave-... 

FIGURE 45.9 Schematic of a confocal LIP detection system with source, optics, and detector shown. The optics include mirrors (M), laser line filter (LF), half-wave plate (X/2), polarizer (pol), dichroic beamsplitter (DB), microscope objective (MO), pinhole (ph), filter, and achromat lenses (achr). The source shown is an argon ion laser, and the detector is an avalanche photodiode (APD). While the electrophoresis channel shown here is in a capillary (CE), the system could be readily applied to a microchip. (Reprinted from Johnson, M.E. and Landers, J.P., Electrophoresis, 25, 3515, 2004. With permission.)... 

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