Dispersion(色散) Refractive index n depends on wave length http://gallery.hd.org/_c/natural-science/prism-and- refraction-of-light-into-rainbow-AJHD.jpg.html 6
Dispersion (色散) • Refractive index n depends on wave length 6
Optical principles of imaging Objective “Lens” Focal length “Object Plane” “Image Plane” D -u f Magnified Light Object is placed image win 1 and 2fof Source the objective lens 1st image 1,11 and M=v-I=Y u v f u
Optical principles of imaging 7
Magnification in Compound Microscope (transmission illumination) Final image projected Condenser Objective onto a aperture aperture screen or Object Projector film (specimen) lens Objective lens First image Final image B Light Source Condenser lens 2 vl v2 M=M,M,=--) f Total mag.is product of mags.for each lens. 8
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b' The image we Eye human being see Eyepiece 目镜 b a F'o Objective 物镜 Specimen 8. a
The image we human being see 9 25 cm 物镜 目镜 Least distance of distinct vision (明视距离)
Magnification vs.resolution ·Magnification -The ratio of image to object. -Calculated by linear optics. ·Resolution -The ability to distinguish two points. 。Limit? 10
Magnification vs. resolution • Magnification – The ratio of image to object. – Calculated by linear optics. • Resolution – The ability to distinguish two points. • Limit? 10