RustyCrampon wrote:

I'm looking for a cheapish (under £100) B&W CCTV camera (with composite
output) to monitor a field on moonlit nights.
I've got a B&W CCTV bullet camera which claims a sensitivity of
0.005lux, but in reality it can't see much.

The Sony EXview-HAD sensors are quite good (colour during daylight, B/W
at night) it could see in "total" darkness indoors let alone moonlight,
but if you're disappointed by 0.005 lux dedicated B/W cameras, they may
not suit as they seem to be 0.01 lux in B/W mode