Assertion: electron microscope | /r/HasAspect | variable-focus lenses
Facets:
value: unlike the optical microscope
type: OTHER
Source sentences:
text: Unlike the optical microscope, in which the lenses are of fixed focus and the distance between specimen and objective lens is varied, the electron microscope has variable-focus lenses, and the distance between specimen and objective lens and the separation of the lenses remain constant.