Practical Aspects See: 1) anatomy/anatomy.htmlhttp://micro.magnet.fsu.edu/primer/ anatomy/anatomy.html 2) anatomy/specifications.html 3) Murphy: Pgs 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 = 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:
Objective Specifications
Why can a high resolution objective cost $4000?: Correction of Geometrical Aberrations Monochromatic: Spherical, Coma, Astigmatism, Distortion, Curvature of Field Chromatic: Longitudinal, Lateral
Spherical Aberration
Coma
Astigmatism
Distortion
Curvature of Field
Chromatic Aberration
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
Chromatic Correction
Plan Objectives
Apochromat Objectives
Mechanical Lengths
Objective Specifications
Parfocal Distance and Turret Mount
Tube lens and Chromatic Correction: Leica-200mm, in tube lens; Zeiss-160 mm, in tube lens; Olympus-180 mm, in tube lens Nikon-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… Olympus “ 60X “ “ … Zeiss Plan Acro 100X/1 water… 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 ~ NA obj 2 /M tot 2 Lateral Resolution: -Fluorescence: r = 0.61 /NA obj -Trans-Illumination: r = /(NA obj + NA cond )
Objective Immersion Type Dry (no marking) Water (direct)W.WI Water (coverglass)W Korr GlycerolG, Gly OilOil, Oel Multi-immersionImm (Water, glycerol, oil)
Objective Special Use Phase ContrastPh1, Ph2, Ph3 Polarized LightPol, DIC UV fluorescenceU-, U340/380 DarkfieldIris 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: mm # 1: mm # 1.5: mm; 0.17 mm for Dry Obj. # 2: mm # 3: mm
Correction Collars for Spherical Aberration
Muli-Immersion and Variable Coverslip Thickness Objectives
Front Element Design in Oil Immersion Objectives
Why Use A Water Immersion Objective
Anti-Reflection Coatings Reduce Scattered Light
nm Uncoated glass n= 1.52 Single layer coating Multilayer coating
Relative Transmission of Objectives (%) Name nm Fluor 40X/ “““ X/0.9 water5688 Planapo 40X/1.2 water
Abbe Condenser
Achromatic Condenser
Aplanatic Condenser
Swing-Out Top Lens Condenser
Ocular or Eyepiece
Ocular Designs
Stage and Eyepiece Micrometers for Microscope Distance Measurements
Projection Oculars
Elements of a Simple Stage
Higher Quality Specimen Stage
Circular stage
FRAP Scope with Cooled CCD Camera
Inverted Microscope Stage
Inverted Microscopes and Micromanipulation
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)