功能

• An achromatic lens with a negative focal length.
• By combining two lenses with different refractive index wavelength dispersion into a single concave lens, chromatic aberration and spherical aberration can be reduced compared to a single spherical lens.
• Optimized to minimize aberration and reduce focal length deviation across the visible spectrum.
• It can be combined with a positive focal length achromatic lens into a Galileo-type beam expander.
• It is corrected not only for aberrations of the on-axis object point, but also for off-axis coma and astigmatism.
• * The chromatic lens has an orientation that allows parallel light to enter the lens.
• * This function allows parallel light to enter from the side of the face with a small radius of curvature (the face pointed to by the arrow).
• * When parallel light is incident from the opposite side, chromatic aberration and spherical aberration occur, and the condensing spot becomes larger.
• Chromatic aberration may increase when the camera is used at wavelengths other than visible light.
• * Also, transparency may be reduced.