Deep Sky or the photography of the invisible
We start talking about real astrophotography in photo history when photos are more than just experiments. The start of astrophotography is situated in 1850 (Michael Maunder, the Photohistorian, 09/2005)
Photographers and astronomers of the 19th century were confronted with two restrictions when photographing stars: the low sensitivity of the Daguerrotype and the errors of the telescopes. Since the Earth turns around its axis, it's almost as if the stars evolve around an imaginary point (the polar star). Take a look at the nice picture by J.R. Eyerman, 1950. These are 2 problems that modern amateur photographers still have to cope with.