Leica DM IRB manual

Brightfield illumination with condensers 0.53 S23 and 0.90 S1

Brightfield illumination is possible with condens- er 0.53 S23 with objective magnifications from 5x to 100x, and with condenser 0.90 S1 from 10x to 100x. A P 1.40 OIL S1 condenser top is available for extremely high resolution.

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Brightfield illumination is possible with objective magnifications of 2.5x to 40x.

Turn a 10x objective into the light path and focus the specimen with the coarse and fine drive. Narrow the aperture diaphragm until you obtain the desired image contrast.

0.30 S70

Brightfield illumination with condenser

Setting the condenser

Illumination techniques where the empty areas The aperture diaphragm determines the lateral of the specimen are the brightest parts are resolution, field depth and contrast of the called brightfield. Absorbing specimen struc- microscope image. The best contrast is tures are required for brightfield imaging, i. e. obtained when the apertures of the objective most specimens will need staining. Alternati- and the condenser are roughly the same.

ves are optical contrasting techniques such as When the aperture diaphragm is stopped down

phase or modulation contrast.to be smaller than the objective aperture, resolving power is reduced, but the contrast is enhanced. A noticeable reduction in the re- solving power is observed when the aperture

On the TL illumination column there are height diaphragm is stopped down to less than 0.6x of markings – S70, S23 and S1 – (13.3) for setting the objective aperture and should be avoided the correct condenser height. Using the where possible.

supplied hexagonal screwdriver, slacken the screw (14.1) and adjust the height of the condenser or condenser holder until its upper edge coincides with the corresponding con- denser height marking on the illumination column. Retighten the condenser or condenser holder fixing screw.

Setting the aperture diaphragm

Brightfield illumination

Operation of transmitted light