"Dave Liquorice" wrote in message
ll.co.uk...
On Mon, 28 Sep 2009 09:37:31 +0100, dennis@home wrote:

A 150W halogen on a PIR or two is much better, it wastes less energy, it
is brighter, it is whiter, and you can see intruders as it goes from
dark to light suddenly.

Intruders that then run off and hide the deep shadow outside of the
brightly lit area from the halogen... "Security" lighting is no good
if it gives people places to hide, you either need to light up the
entire area to the same high level or just have low level light so
they can be seen but there are no deep shadows to hide in.

Security lighting is no good if you are so used to it being on you don't
look.
With the PIR you know something has set it off and it will come on again as
soon as they move.


Work/play lighting is different but a single source bright isn't good
for that as you get the deep shadows when you have the light level
high enough to be useful.

You only get deep shadows if you put the light in the wrong place, if its at
head height near where you stand you won't see any shadows, pretty well like
holding your torch next to your ear.