Microscopes -- Definition and measurement of illumination properties -- Part 1: Image brightness and uniformity in bright field microscopy
ISO 19056-1:2015 defines how image brightness and uniformity are measured and how this information is provided to the user.
NOTE The scope is intentionally limited to electronic imaging devices and (intermediate) image planes. The visual observation by means of eyepieces would require a different measurement procedure and hence result in unambiguities in the description of measurement procedures. Nevertheless, this part of ISO 19056 will give useful estimates for the image brightness with visual observation as in this case, an eyepiece is used to observe an intermediate image plane (which is under the scope of this part of ISO 19056).