Imaging characteristics of three cameras using the Scheimpflug principle.

We studied the handling and the potentials of three different cameras operating according to the Scheimpflug principle and which currently are commercially available. The examinations were performed with the cameras Topcon SL-45, Topcon SL-6E with cataract attachment and Zeiss SLC system. Pigmented Brown-Norway rats with ultraviolet-B-induced cataract were used as the examination model. The image characteristics of the three cameras can be summarized as follows: The Topcon SL-45 camera produces very sharp images with small distortion; the Tocpon SL-6E camera with cataract attachment has the advantage to record simultaneously a slit image and a retroillumination image on the same film frame, but the slit image is quite distorted at the vertical axis; as regards the Zeiss SLC system, the quality of the video image is not as good as a film negative; however, this camera offers a superimposed image to the observer for easy orientation, as for example with small animal eyes. In addition, the direct quality control of the image on the screen increases the reproducibility significantly. However, the slit image is quite distorted at the horizontal axis.