Just made a trip to the new Bromley Picturehouse (the former Odeon/ABC/Empire/Cineworld depending on how long you've lived in the area! - near the Magistrates' Court) for the first time: they've done a fine job on it, restoring the Art Deco aspects, with stadium-style seating in the screen I was in, at least, so no heads in the way. Could perhaps make more of the foyer than they've currently done, though. Films £7 on Monday nights, I believe.
There's quite a bit of competition in this area now (how weird it seems to say that after all these years!), but it might actually be a good option depending on where you live in Sydenham - trains from Penge East, a roundabout bus route from Lower Sydenham, or quicker bus routes from over the Penge side.
Bromley Picturehouse
Re: Bromley Picturehouse
Agree with this. Even more, Everyman Crystal Palace, which we walked to