Named after August Kopff - German astronomer (1882-1960).
Kopff is a lunar crater that lies along the eastern edge of the inner Mare Orientale impact basin, on the western limb. In this position the crater is seen from on edge from the Earth, and its visibility is affected by libration. This situation makes it difficult to discern much detail about the crater unless it is viewed from orbit. At one time this crater was considered to have formed due to volcanic activity, in contrast to most lunar craters which are considered to have been created through impacts. (wikipedia entry)