シェードオフおよびハロー位相差アーチファクト

Two very common effects observed in phase contrast images are the characteristic shade-off and halo patterns in which the observed intensity does not directly correspond to the optical path difference (refractive index and thickness values) between the specimen and the surrounding medium. This interactive tutorial demonstrates shade-off artifacts in positive and negative phase contrast microscopy.
Contributing Authors
Douglas B. Murphy - Department of Cell Biology and Anatomy and Microscope Facility, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, 107 WBSB, Baltimore, Maryland 21205.
Kenneth R. Spring - Scientific Consultant, Lusby, Maryland, 20657.
Matthew Parry-Hill and Michael W. Davidson - National High Magnetic Field Laboratory, 1800 East Paul Dirac Dr., The Florida State University, Tallahassee, Florida, 32310.