PCPaul wrote:
On Mon, 04 May 2009 21:18:12 +0000, The Medway Handyman wrote:

So that confirms that sunlight is stronger or of different wavelength
than internal lights.

Both.


It's far stronger - I have a nominal 250W 'daylight spectrum' bulb and
the sun through the window still casts shadows when it's on.

The sun is also much wider spectrum than any bulb - around 300-2500nm
wavelength at ground level. We can only see 400-700nm(ish). Even top
quality 'daylight spectrum' bulbs don't bother trying to match the
further reaches of Ultraviolet or Infrared - and we can be glad they
don't...

Yerbut, nobut, yerbut. At the front of handyman towers I have a dawn dusk
lantern (no PIR) with an 11w thingy bulb (sorry, lamp) and about 8' away on
the front of the garage I have a 500w halogen light (manually switched, no
PIR).

If I'm loading the van at night & switch on the 500w jobby, the dawn dusk
goes out, until the 500w is switched off again. So (a) how come the 11w
lantern doesn't switch itself off evey time it switches on and (b) its seems
to react to a 500w halogen just like sunlight.

My brain hurts...


--
Dave - The Medway Handyman
www.medwayhandyman.co.uk