Wiktionary
demagnify
vb. To reduce the size of an image etc
Usage examples of "demagnify".
This, when you demagnify it by 25,000 times, is still 80 angstroms in diameter---32 atoms across, in an ordinary metal.
We can reverse the lenses of the electron microscope in order to demagnify as well as magnify.
The few electrons which come from the photoelectric screen are demagnified down to a very tiny area so that, again, they are very intense.