Fig. 1. Schematic of zoom optical system

Fig. 2. Optically comensated zoom system. (a) Two-component system; (b) three-component system; (c) four-component system

Fig. 3. Four-component mechanically compensated zoom optical system^[21]. (a)PNNP form; (b)PNPN form; (c)NPNP form; (d)PNPP form

Fig. 4. Light path of two optical microscope systems. (a) Finite conjugate system; (b) infinite conjugate system

Fig. 5. Continuous zoom stereo microscope optical system with double linkage moving lens groups

Fig. 6. Binocular microscope with eyepiece adapter

Fig. 7. Magnification variable eyepiece adapter optical system of finite conjugate microscope^[32]

Fig. 8. Handheld continuous zoom digital microscope

Fig. 9. Continuous zoom optical system with finite conjugate distance for zoom ratio of 9.3×^[33]

Fig. 10. Optical system of 0.7×-5.6× continuous zoom digital microscope with finite conjugate distance^[34]

Fig. 11. Infinite single tube continuous zoom digital microscope system

Fig. 12. Electric continuous zoom lens

Fig. 13. Guide electric zoom lens

Fig. 14. Optotune liquid lens^[38]

Fig. 15. Edmund optics continuous zoom lens with liquid lens