This tutorial explores how the size and angle of substage condenser light cones vary with the size of the aperture diaphragm opening and numerical aperture. Instructions for operation of the tutorial appear under the applet window.

	Interactive Java Tutorial
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The slider controls the operation of this tutorial by changing the size and angle of the condenser light cone. Moving the slider to the left decreases both the opening size of the aperture diaphragm and the numerical aperture (and light cone) of the condenser. Alternatively, moving the slider to the right has the opposite effect.