We might all know him for his work with Monroe, but Milton Greene also took hundreds of photos with Dietrich.
His most famous shots of Marlene may be this 1952 shot used on the cover of Life Magazine:
And these 1972 shots, with the still-sexy Dietrich wearing nothing but her swan feather souffle (and her 'foundation' of course):
But the Milton Greene archive, found here, includes a LOT more pictures of Dietrich. If you don't mind looking through 16 pages of contact sheets (not all well scanned), it's worth a look, or two!
My favorite shot is the following: