【正文】
ndenser ? objective ? diaphragms ? lamp power specimen plane eyepoint image formed by objective condenser aperture diaphragm field stop diaphragm 31 Adjusting Microscope for Koeher Illumination 2. Lamp fills the front aperture of the condenser Purpose: to achieve Koeher Illumination Tool: eyepiece telescope or Bertrand lens ? condenser ? objective ? diaphragms ? lamp power 32 Adjusting Microscope for Koeher Illumination 3. Focus the specimen Purpose: to achieve Koeher Illumination Tool: eyepiece telescope or Bertrand lens ? objective ? focus dials ? stage controls NOTED: avoid objective plunge into specimen slide 33 Adjusting Microscope for Koeher Illumination 4. Focus and center the condenser Purpose: reduce scattered light and improve image contrast ? condenser ? field diaphragm ? lamp power 34 Adjusting Microscope for Koeher Illumination 5. Adjust the condenser diaphragm Purpose: to obtain the best resolution and contrast Tool: eyepiece telescope or Bertrand lens ? condenser diaphragm NOTED:~3/4 of the maximum diameter of the aperture 35 Adjusting Microscope for Koeher Illumination 6. Adjust the brightness Purpose: to obtain optimal image brightness ? voltage ? neutral density filters NOTED: aperture diaphragm should never be closed downs as a way to reduce light intensity 36 37 38 39 40 41 42 Detectors for Optical Microscopy ? Film photomicrography ? Video imaging (Close Circuit TV) ? Digital imaging with a charge coupled device (CCD) ? Scanning microscopy – Photomultiplier tube (PMT)光電倍增管 – Avalanche photodiode (APD)雪崩光電二極管 4