The series with large working distance represent the entry level for inverted microscopy. They are corrected for cover glass and vessel bottom thickness up to 2 mm. This means optimal in the main applications of LD objectives, such as observation through thicker cell culture vessels etc. But also the use of thinner cover glasses for example in the range of 0.17 to 0.6 mm is easily possible with the simple use of a cover glass cap. The available contrast methods are ranging from brightfield, phase contrast to VAREL, Hoffman Contrast up to PlasDIC, the Zeiss exclusive polarization optical differential interference contrast, that makes applications like ICSI now possible even in plastic vessels with high resolution and brilliant contrast. Of course they are also suitable for fluorescence applications with excitation wavelengths within the visible spectrum.