The 'through focus plate' : a simple method for obtaining images through focus on a single photographic plate in the...

Tilting the specimen in an electron -icroscope by a relatively small angle can provide a continuous through focal series on a single plate, as the displacement of the object at the edge of the field can be adjusted to be of the same order of magnitude as the alteration of focal point by the fine lens controls. This simple rapid manoeuvre could have applicaitons in the microscopy of uniform preparations, particularly if the specimen is subject to beam damage, and in assessing microscope performance rapidly.