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Practical Aspects. See: 1) http://micro.magnet.fsu.edu/primer/anatomy/anatomy.html 2)http://micro.magnet.fsu.edu/primer/anatomy/specifications.html 3) Murphy: Pgs 50-60 E. D. Salmon University of North Carolina at Chapel Hill. Homework Problem 5.
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Practical Aspects See: 1)http://micro.magnet.fsu.edu/primer/anatomy/anatomy.html 2)http://micro.magnet.fsu.edu/primer/anatomy/specifications.html 3) Murphy: Pgs 50-60 E. D. Salmon University of North Carolina at Chapel Hill
Homework Problem 5 The light source is a 3-mm square tungsten filament. The design of the illumination system requires that (1) the filament be 300 mm away from the condenser diaphragm, (2) the image of the filament must be in focus at the condenser diaphragm and (3) the filament must be 15-mm square to fill the condenser aperture with light. Assuming the lamp collector lens is an ideal thin lens, determine the focal length, and the position of the collector lens between the lamp filament and the condenser diaphragm. Ans: Eqn 1: M = i/o = 15/3 = 5; i = 5o Eqn 2: i+ o = 300; 5o +o = 300; o = 300/6 = 50; i = 250 Eqn 3: 1/i +1/o = 1/f; 1/250 +1/50 = 1/f; f = 41.67 mm
Homework Problem 6 A field diaphragm or iris is placed in front of the collector lens as shown for the Koehler illumination system. The field iris is used to control the illuminated area of the specimen. The condenser lens is translated back and forth along the central axis until an image of the field diaphragm is in sharp focus on the specimen. When the opening of the field diaphragm is 20 mm, the image on the specimen must be 2 mm in diameter. In addition, the field diaphragm is placed 160 mm away from the condenser lens. What is the focal length of the condenser needed to meet these requirements? Answer: Eqn. 1): 1/o +1/i = 1/f, or 1/160 +1/i = 1/f and Eqn. 2): M = i/o = .1, so i = .1 *160 = 16 mm Solving Eqn 1 1/160 +1/16 = 1/f; f = 14.5 mm
Homework Problem 7 Indicate “In-focus” or “out-of-focus”for: Field Diaphragm Light Source at: Field Diaphragm ____In_______ ______Out___ Condenser Diaphragm ____Out______ ______In____ Specimen ____In______ ______Out___ Objective BFP ____Out______ ______In____ Ocular FFP ____In_______ ______Out___ Ocular BFP (Ramdens Disk) ____Out______ ______In____ Retina (or camera detector) ____In_______ ______Out___
Homework 8 Work through the Microscope Illumination Section under Microscope Anatomy at: http://micro.magnet.fsu.edu/primer/index.html
Why can a high resolution objective cost $4000?: Correction of Geometrical Aberrations • Monochromatic: Spherical, Coma, Astigmatism, Distortion, Curvature of Field • Chromatic: Longitudinal, Lateral
Chromatic (and Spherical) Aberrations Corrected by the Achromatic Doublet Chester More Hall Makes the Discovery in 1730, diddles, and John Dolland Learns the Secret, and Patents it in about 1759.
The 3 Classes of Objectives Chromatic and Mono-Chromatic Corrections
Tube lens and Chromatic Correction:Leica-200mm, in tube lens;Zeiss-160 mm, in tube lens;Olympus-180 mm, in tube lensNikon-200 mm, in objective
Working Distance of Some Objectives (mm) • Zeiss PlanApo100X/1.4 oil……..0.1 • Olympus “ “ “ “ …….0.2 • Nikon PlanApo 60X/1.4 oil……..1.1 • Zeiss PlanApo 40X/1.2 water…..0.22 • Olympus “ 60X “ “ …..0.22 • Zeiss Plan Acro 100X/1 water…..1.00 • Nikon Fl 40X/.75 air…………….0.51 • Nikon Fl 40X/.7 LWD air……….2.? • Nikon Fl 10X/.30 air…………….10
Importance of Objective NA • Light Collection: I ~ NAobj2/Mtot2 • Lateral Resolution: -Fluorescence: r = 0.61l/NAobj -Trans-Illumination: r = l/(NAobj + NAcond)
Objective Immersion Type • Dry (no marking) • Water (direct) W.WI • Water (coverglass) W Korr • Glycerol G, Gly • Oil Oil, Oel • Multi-immersion Imm (Water, glycerol, oil)
Objective Special Use • Phase Contrast Ph1, Ph2, Ph3 • Polarized Light Pol, DIC • UV fluorescence U-, U340/380 • Darkfield Iris in BFP
Dry Objectives must correct for refractions at air/coverslip interface; Oil immersion Increases NA
Cover Slip (see below) and Slide Thickness: Slide is 1 mm thick; both have n= 1.52 crown glass • # 0: 0.1-0.13 mm • # 1: 0.13-0.17 mm • # 1.5: 0.15-0.20 mm; 0.17 mm for Dry Obj. • # 2: 0.17-0.25 mm • # 3: 0.25-0.5 mm
Anti-Reflection Coatings Reduce Scattered Light 5 4 3 2 1 0 Uncoated glass n= 1.52 Single layer coating Multilayer coating 400 500 600 700 800 nm
Relative Transmission of Objectives (%) • Name 320 350 400 500 600nm • Fluor 40X/1.3 16 66 80 90 91 • “ “ “ 29 79 88 95 99 • 40X/0.9 water 56 88 • Planapo 40X/1.2 water 20 54 86 89 92
Stage and Eyepiece Micrometers for Microscope Distance Measurements
Modern Upright Research Light Microscope (1995) *Bright, High Contrast Optics *Epi-Fluorescence *Phase-Contrast *Polarization *DIC *Diffraction Limited Resolution *Multiple Ports *Auto. Photography *Electronic Imaging- (Video---CCD)