The Best Telescope Objectives, And Photographic Objectives Intended For Three Colour Work, Are Also Apochromatic, Even If They Do Not Possess Quite The Same Quality Of Correction As Microscope Objectives Do.
In consequence of its low refractive and dispersive power, colourless pellucid fluor-spar is valuable in the construction of apochromatic lenses, but this variety is rare.
Abbe in 1886 in the so-called apochromatic objective.
36.- Apochromatic system.
Abbe succeeded in computing microscope objectives free from error of the axis point and satisfying the sine condition for several colours, which therefore, according to his definition, were " aplanatic for several colours "; such systems he termed " apochromatic."