Philip H. Jones, Onofrio M. Maragò & Giovanni Volpe
Fig. 8.3 — Objectives
(a) Oil-immersion infinity-corrected 100× apochromat objective showing the definitions of working distance, parfocal distance and back aperture. (b) Cutaway diagram showing the lens system inside a typical 100× apochromat objective. (c)–(e) Cutaway diagrams showing the increasing complexity of the lens system inside a 10× objective for higher degrees of correction: (c) achromat; (d) fluorite (semi-apochromat); (e) apochromat.