Phase contrast objective (Plan 20PH) with slider

With the phase contrast technique, mostly uncoloured probes or thin cells are examined. Basicly, it is the observation of an interference picture. Here, the light rays (full Köhler illumination and phase contrast condensor are necessary!) are divided by a ring iris. The light is guided through the probe and partially beneath it. Depending on the probe´s internal structure, a phase difference occours compared with the background light. For interferometry, it is necessary to reunite both light paths; their phase differences are the information carrier. For this, you need one phase contrast objective (optically, it is a plano-objective with an additional phase plate) and a dedicated phase slider. Both parts are designed to work with each other and cannot be interchanged with other lenses or sliders.

For optimal results, we strongly recommend the optional collimation telescope if you don´t already have one (see accessories section). With this handy system, both parts of the phase contrast system can be aligned exactly.