Resolution of human eyes μ=133 Object μ=1 Image μ=1.38 Iris is a variable μ=138-1.41 aperture that adjusts intensity of Optic nerve detects signal light allowed in. projected onto retina by curved lens. ~0.2 mm 25 cm distance 11
Resolution of human eyes 11 ~0.2 mm @ 25 cm distance
Resolution of a microscope Resolution- Minimum distance between two point objects that can be distinguished. (b) 12
12 Resolution of a microscope Resolution Minimum distance between two point objects that can be distinguished
Resolution of a microscope Ro 0.6121 △ro= M nsina nsina:numerical aperture(数值孔径，NA) n:refractive index of the medium between the object and objective lens a:half angle of the light cone Visible Light: λ~6000A X-rays: λ0.5-2.5A Electrons: 1~0.05A
13 Resolution of a microscope nsin : numerical aperture (数值孔径,NA) n: refractive index of the medium between the object and objective lens : half angle of the light cone
Question What is the resolution of an optical microscope? ·Answer:0.15-0.20um 14
Question • What is the resolution of an optical microscope? • Answer: 0.150.20 m 14