Electron penetration into the sample in the scanning electron microscope can give rise to bright fringes close to sharp edges in the secondary electron image. This can make it difficult to see details close to the edge. These fringes can be considerably reduced by putting a positive control electrode (CE) between the specimen and the collector. This can be mounted with an insulated clip directly onto the specimen stub. The effectiveness of this technique is demonstrated for the case of a cleaved silicon wafer containing microelectronic structures. The action of the CE is explained in terms of the effective solid angle subtended by the collector at the surface of the specimen. Copyright © 1986 Foundation for Advances in Medicine and Science, Inc.