Abstract
We proposed a microscopy method for observing phase objects without halos or directional shadows.
The key optical element is an annular aperture at the front focal plane of a condenser with a larger diameter
than one used in standard phase contrast microscopy. The light flux passing through the annular aperture
is changed by the specimen’s surface profile, and then it passes through an objective and contributes
to image formation. Images of colonies, formed by induced pluripotent stem (iPS) cells using this
method, are compared with the conventional phase contrast method. Our method obtains phase images
of iPS cell colonies with clear outlines and their three-dimensional nature
