Cannot figure out what this is asking and cannot find scholarly article

Rheinberg Illumination. For Rheinberg

illumination you should take a picture of a sample (the sample

should have similar properties as the one used for Darkfield) with and without the Rheinberg filter in

place. You should then use a graphics program with the unstained sample in order to show

how you can

highlight the same structures in the same way by computer skills. In addition, to the technique

information, you need to draw a picture of the filter that

was used to create the picture

for this technique

(color specific)