Different applications require different testing qualities and therefore different demands on image quality and image evaluation on the monitor.
The monitor classes are defined by the test quality requirements:


There is an ongoing discussion if MK4 is needed - just say, if you do not evaluate the image on the monitor, you do not need a specification. MK4 shall be skipped.

The German DIN 6868-157 for medical monitors have minimum requirements for image reproduction devices in seven monitor classes. The maximum requirement to the luminance is 300 cd/m² and to the luminance ratio 250.

Latest discussed questions with results:
- minimum monitor diagonal: 17 inch
- maximum pixel size: 300µm (requirering distant viewing)
- minimum pixel size: 85µm (300dpi) otherwise, details may be too small to be recognized. With smaller pixel size a scaling with an Integer is required (see thread about Windows scaling).