The Tektronix IsoVu Isolated Measurement System makes great use of the advantages of optical technologies such as high bandwidth, galvanic isolation, and extreme common mode voltage rating.  But, it also inherits the idiosesyncrasies and foibles of fiber-optic technologies.  However, fiber optic communication companies have been documenting and designing around many of these problems for years, and Tektronix IsoVu designers have leveraged that mature industry to create an easy-to-use system.  Most accommodations are already implemented in the IsoVu firmware with only a few characteristics of which any user of IsoVu should be aware. This technical brief describes the remaining performance non-idealities and provides workaround strategies.