Due to its limited depth of focus, the conventional slitlamp photography is not suitable for the documentation of a total lens section which depends on a sufficient depth of focus. By applying the Scheimpflug principle it is, however, possible to demonstrate the optical section through the lens as a slit image which is nearly undistorted and shows sufficient depth of focus. An integrated instrument based on the Scheimpflug principle has been developed, and the present paper demonstrates its importance for clinical and experimental use. After densitometric evaluation, these photos enable to obtain hard data on normal and pathologically changed lenses. Different densitometric methods may be employed for the evaluation. Experiences with the equipment from running clinical test series are reported.