In article ,
"Johnny OneSpanner" writes:
Hello -

In response to local burglaries, some relatives have been advised by the
police to install a dusk-to-dawn low-level floodlight in their small (15
metres across) farmyard., which already has motion-activated halogen lamps.

The police recommend a sodium lamp, but are the CFL-based floodlights also
suitable?

Yes, but they're less efficient, both the raw lamp itself, and because
it's not possible to design luminare optics for such a large light source
as efficiently.

Sodium lamps with dusk-til-dawn sensors seem to be quite thin on the ground,
should I use a separate sensor?

Yes, but you should go and try an electrical wholesaler, who
will have a better selection than ScrewFix.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]