Apochromatic objectives for amateur and professional astronomy

摘要

This paper discusses the features of objectives intended for amateur and professional astronomical observations. Type-OK4 crown glass with special dispersion behavior is used to achieve apochromatic correction in refracting objectives, since the technology for obtaining high-quality blanks made from this glass makes it possible to create apochromatic objectives with an entrancepupil diameter of up to 304 mm. Experimental compositions of the glass have been developed that make it possible to obtain apochromatic systems composed of two lenses.