Zeiss Axio Scope.A1 Operating Manual

Contents

OPERATIONCarl Zeiss Illumination and Contrasting Method Axio Scope.A176 M60-2-0007 e 05/084.1.4 Adjusting the Transmitted Light/Differential Interference Contrast (DIC)(1) General principle of operationThe transmitted light/DIC method allows for a high-contrast vivid display of transparent sample details.The light is linearly polarized by a polarizer and is separated into two beams in a birefringent prism. Thetwo beams penetrate two parts of the sample which are closely separated. They experience different pathdifferences due to the different refractive indices or different sample thickness. Both beams are thenreunited in a second double refractive prism and have after passing the analyzer the same polarization.Therefore both beams can interfere in the intermediate image and the path differences are thusconverted into intensity differences represented by a grey scale. A compensator or λ-plate may be usedfor a consecutive conversion of the grey scale in a color scale.(2) Instrumentation− Objectives equipped with DIC fixtures, e.g. EC-Plan-Neofluare− Nosepiece with slot for DIC slider− DIC slider, compatible with the objectives in use− Condenser with turret disk containing DIC prisms (e.g. condenser, achromatic-aplanatic 0.9 H D PhDIC)− Analyzer module ACR P&C for transmitted light in the reflector turret/slider or analyzer slider D/Afixated or rotatable in connection with a mounted intermediate plate for analyzer slider 12x46− Rotatable mechanical stage, if necessary(3) Adjusting transmitted light/DIC• Put the DIC compatible objective (637H637HFig. 4-6/3) in place on the nosepiece. Slide the according DIC slider(6 3 8 H 6 3 8 H Fig. 4-6/1) into the slit of the appropriate objective position. Make sure that the slider engages firmly.• Swing in the analyzer module (639H639HFig. 4-6/6) on the reflector turret (6 4 0 H 6 4 0 H Fig. 4-6/7) (or slide the analyzer sliderinto the intermediate plate for analyzer sliders).• Swing in the DIC prism (position DIC on the condenser (641H641HFig. 4-6/4).• Adjust field diaphragm and aperture diaphragm according to the KÖHLER method.• Adjust the optimal contrast on the DIC slider (642H642HFig. 4-6/1) with the knurled screw (643H643HFig. 4-6/2).Symmetrical adjustment of the DIC slider along its middle position lets the sample details appear as ifthey were elevated or deepened.• If desired, the compensator λ (6 4 4 H 6 4 4 H Fig. 4-6/5) can be put into the opening above the nosepiece in order tocreate a chromatic DIC contrast.The DIC method functions with polarized light. It is disturbed when birefringent elements, e.g.foils, are put between polarizer and analyzer, as is sometimes done when doing a histologicalincision. The same situation occurs with Petri dishes or specimen holders which have a plasticbase. In these cases we advise using PlasDIC.