“+ adjective
Etymology: phot- + visual
: having the same focal length for actinic rays and for the brightest of the visual rays — used of an achromatic lens
“+ adjective
Etymology: phot- + visual
: having the same focal length for actinic rays and for the brightest of the visual rays — used of an achromatic lens
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012