1 Scope
This part of ISO 19012 specifies the use of the marking “Plan” on microscope objectives, and defines the diameter of the sharp region of the primary image of a flat object surface. This part of ISO 19012 applies to visual observation using the combination of objective lens, tube lens and eyepiece, as specified by the manufacturer.
This marking is consistent with ISO 8578.
NOTE The flatness of the image field does not imply any degree of correction for other aberrations (ISO 10934-1).