On Fri, 14 Dec 2007 18:41:10 +0000, Peter Parry wrote:

It is possible to tell the "floodlight" (more a damp fog than a flood)
is on without having to use night vision goggles, but only if you look
directly at the light.

The site that was posted earlier also does LED floods with a goodly number
of LEDs. Of cousre you still have the issue of runtime from a battery and
how to charge that in the 6hrs of daylight you get at this time of year.

Commercial LED lighting has certainly taken a big leap in the last year or
so with devices with 1W or more ratings.

If you stand outside with your eyes closed for 30 minutes, and have no
other light sources within several miles to ruin your dark adaptation,
then when you open your eyes you can detect white painted dustbins and
similar large objects up to a range of nearly 2metres from the light.

Not if it's cloudy. It will be dark, real dark, can't see a thing dark, no
matter how dark adapted your eyes are. Star light is ample for moving
about without bumping into things but it doesn't penetrate cloud well,
neither does Moon light... Most places in the UK probably have more than
enough sky glow though, we don't. It's actually a bit unnerving standing
outside knowing your eyes are open but not being able to see anything.

--
Cheers
Dave. pam is missing e-mail