Mesopic Park
Just when you thought it might be safe to go out at night, it turns out that we’ve all been seeing it wrong. How do I know this? Because of the work done by a bunch of Euro-boffins under the banner of the Mesopic Optimisation of Visual Efficiency project, or MOVE – for the sake of sanity. Checking the wacky world of the web, it seems that this study was wrapped back in 2004, but the stake in the heart obviously didn’t take because its findings have been discussed recently in one of our learned lighting journals (that’ll be Lighting Journal, then.) And what were they looking for, these MOVE chappies: The lack of mesopic scales results in inappropriate lighting, energy wastage and decreased traffic safety. The objective is to define scales for the mesopic range (0.001-3 cd/m2) and to establish appropriate working practices that are accepted throughout the European Community. Oh dear.
Let me give you a firmer footing on this one, just so’s you stay with me. Back at the end of the ‘60s, Phil Spector released his entire oeuvre in a 4-disc compilation called ‘Back to Mono’. As well as it being a great ego-boost for the old convicted-murderer-to-be it was a protest against the growing aural complexity that led to bands like Emerson Lake and Palmer, of whom – ‘nuff said. Keep that simple phrase between your ears for the next few minutes; ‘Back to Mono’.
Back to the plot: the dust of the MOVE project has been mixed with the blood of an innocent lighting designer and now stalks that hinterland betwixt day and night: The Mesopic. Where we’ve all been going wrong is in assuming that we only have one pair of eyes. How foolish of us. As any fule kno, our eyes are shifty critters who gad about without so much as a by-your-leave. During the day they prefer the yellowy garb of Photopic society - but like the flippertygibbets they are, it’ll be the blues of those Scotopic rascals once the sun has set.
The MOVE coves came up with the idea that we’ve been getting our night-time lighting wrong because we’ve always based it on the characteristics of our daytime vision. But because street lighting levels are all around the Mesopic range, that’s where we should be looking for coloration – and that, my friends, is GREEN. Yes, it deserves repetition: GREEN! And if we’re not careful, that’ll be the colour of the future nightscape, and my skin crawls even as I type it.
And why is this even an option? Because that tricky LED technology has been talking itself up again. Why shouldn’t we shift colours if we want to – if we need to? Presumably, in some future Dorchester, I’ll be able to walk down South Street and shout. ‘Oi! Streetlight! A bit more green, if you please. I feel the Mesopic coming on.’
But here’s another idea; Stop it. Leave it alone. Don’t go there. Back to Mono, where light is light and dark is dark and the Mesopic is just a place of shadows.
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Comments
John,
I do like your rendition! but hey, surely we should be looking at blue and not green. Those ole rods like it that way, green is ok for old ladies, anyhow I like blue, we can back off on the lux and watts and still see in the dark. Surely that's better than the Council turning the beggars off to save energy. Anyhow, I like the dark skies initiative-put the light where it's needed I say-on the ground and not competing with the stars!
Michael Kerton 14-04-2010
John Bullock Lighting Design: 01305 889256
