Abstract
Nowadays, CCDs are the primary imaging technology in astronomy, but not long ago there were photographic plates. Truly, the photographic era has left to us an important heritage of sky imaging, that spans about two centuries in time. Plates are the oldest records of wide fields on the sky, which makes them tremendously valuable for the measurement of stellar proper motions, that is, for photographic astrometry. The existence of plate collections with potentially great scientific value but not yet reduced, and the possibility of using simple and inexpensive technology to digitize them, offer an unprecedented opportunity to take advantage of this first-epoch material, now literally in storage.
