Microscope focusing system
A lens system that moves the focus of a microscope without altering the working distance between the object and objective lens can be used to correct the spherical aberration introduced by cover slides and immersion liquids. The InFocus internal optical focusing system translates the focus above, through, and below the object without external movement. Versions optimized for laboratory use and for industrial use are available.
Infinity Photo-Optical Company, Boulder, CO