It's a new design, but for a '70s-inspired interior, the Celeste ceiling light at John Lewis could be an option.
The light is a mix of metal and glass, with a choice of finish for the former, all of which are pictured here and an exposed bulb visible through the glass shade. Great for a period room, just as good for a room needing a hint of retro.
It is sized around 22 x 25 x 22cm and has a drop of up to 110cm. The price is £80.