Ask Slashdot: Setting Up Non-Obnoxious Outdoor Lighting? 445
An anonymous reader writes "My neighbor recently complained about my outdoor floodlight shining in her window. While trying to address this problem, I read an essay about the tragedy of light pollution, and started to think that this is a much broader issue. With all the new lighting technologies out there, this may be the right time to rethink lighting — both indoor and outdoor; public and private. I solved my problem by replacing the floodlight with a spotlight, but I also considered installing a colored light. What are some strategies for illuminating what we need to without casting excess light everywhere and inadvertently blinding our neighbors or keeping them awake?"
But why? (Score:5, Insightful)
What do you need a floodlight for?
IMHO there is way too much lighting - residential areas just plain don't need outdoor lighting at all; what's wrong with just carrying a torch?
Only use lighting when needed... (Score:4, Insightful)
The simple solution to this problem is to only use lighting when it is really needed, ie. when there is a human within range who wants to have some extra light. As soon as the human is gone, switch of the light. Use a motion sensor adjusted to human-sized objects so it does not trigger every time the neighbour's cat comes wandering by. Aim it so it does not get triggered by passers-by who have no intention of entering the designated area.
Night time is supposed to be dark. Make it so. Turn it off!
Re:Sigh (Score:5, Insightful)
Nope. Pollution is merely a contaiminant introduced into an environment that causes adverse change. Light pollution can have adverse effects on the environment beyond making astronomers cranky. There are also medical studies showing that excessive light has adverse effects on the health on both humans and other animals.
You're simply misinformed and bashing a strawman.
Re:But why? (Score:4, Insightful)
All the studies i checked (sorry no ref, that was 15 years ago) on the subject correlated closely drops of burglary with increase of outdoor lightning in the same area.
But why not explore other sources of lighting? glowing plants [glowingplant.com] for example (they had some success with kickstarter [kickstarter.com] a few months ago)
The real problem (Score:5, Insightful)
The real problem with outdoor lighting is that fixtures are installed incorrectly probably 99% of the time. is there ANY reason that >50% of the light escaping the fixture should be going skyward? Aim the things properly and > 90% of the light pollution problem will go away (what remains is incidental reflection from the ground or scattering by water vapor). I have been in well-lighted gated communities where careful design went into outdoor lighting, and despite the ground being well lit, you still get a great view of the sky.
I am finishing a move to Lee, NH and in my backyard I can see the Milky Way very clearly, and for the first time I can actually spot the Andromeda Galaxy clearly without resorted to averted viewing.
Near me I have two NASCAR tracks and one drag track nearby (Lee Speedway, Star Speedway, and one New England Dragway). Lee Speedway is a short jog through the woods and Friday nights, sky viewing is crap; driving by I checked out the lights, and they're aimed at about a 30 angle, throwing 70%+ of the light up to the sky. I don't mind the noise at all from the track, but the light pollution is very annoying, because when those stupid lights are on I can't see much more in the sky than I can see in Boston. The problem can be solved very easily by aiming the lights correctly. It would still create a light dome from reflected and refracted light, but it would be very minimal.
Most of the problem is due to installer incompetence. There is no reason - no need for these lights to not be aimed properly. In fact, IMHO, it should be part of NEC to require outdoor lighting to be aimed as well as wired and sealed properly.
Best solution: natural starlight (Score:5, Insightful)
I live in a wood in Scotland three miles from the nearest streetlight, half a mile from the nearest other house. I don't have any exterior lights, because I don't need them. There's no more than two nights a year when it's murky enough - usually because of fog - to need a torch. The human eye is extremely good at adapting to low light, if you give yourself a couple of minutes to adjust. And out of doors, on planet Earth, it is literally never dark.
Starlight is a free natural service offered you by the planet which doesn't run up your energy bill or cause light pollution. Use it.
Re:Sigh (Score:4, Insightful)
Just because the benefit outweighs the cost does not mean it is not pollution. It just means the pollution is potentially justified (arguments nailing down the costs and benefits aside). Putting oil slicks on ponds benefits people in some areas by killing mosquito larvae, but that doesn't mean it isn't pollution, even if the costs out weigh the befits. An emergency generator running a hospital during a power outage produces a crap ton of benefits, but that doesn't mean the exhaust is pollution free. The costs don't have to be direct human health costs either, as they can include quality of life costs and damages to wildlife (the latter may be considered part of the former...).
Also, just about every light pollution campaign I've seen isn't arguing removing lighting. It is about using lighting as needed, and not being wasteful. Light designs that seen 10-50% of the light directly into the air are not increasing security, just wasting electricity. Lighting that is uneven is wasting electricity on the excessively bright areas while not providing enough illumination in other ares. In that case, it is large detriment to security, as someone hiding in shadows when your eyes are accustomed to a brightly lit path is even better hidden than if on consistently lit, dim path.
Re:But why? (Score:4, Insightful)
You should inform your landlord that motion sensor lights, and lights in general, do little to deter crime. When you provide lighting it means the criminal doesn't have to use a suspicious flashlight and draw attention to themselves.
To take it to the extreme: if lighting prevented crime then NYC and Paris would be the least crime ridden cities in the world.
Low voltage, perhaps solar/battery powered, lighting in the areas you need it would be best. Point lights, such as spots and floods, are annoying and wasteful as they need to send light from the single point outward across a distance with enough intensity for it to reflect back to your eyes which are dilated to accommodate the very bright light in the foreground which blinds you. Lower wattage lighting distributed around the area you wish to illuminate provides a much more usable light at lower intensity and dispersion levels.
You'd be VERY surprised what a few strings of LED solar yard lights will to to light up your yard completely, but not annoy your neighbors.
Re:But why? (Score:5, Insightful)
Also, raise the light and angle it closer to straight up and down. The it will provide plenty of light but reduce the cast-off. The problem the neighbor faces is usually less a problem of how bright it is, but how direct the light is.
Re:But why? (Score:5, Insightful)
we're not really creatures of the dark.
Not true. Humans function perfectly well in the dark.
Outdoor lighting, overall, is most definitely NOT nice to have, aside from very specific occasions where it is briefly necessary. It's bad for security, bad for aesthetics, bad for sleep, and bad for health (physical and mental).
Re:But why? (Score:2, Insightful)
So I don't need to light up the places where criminals may hide where no-one will see them?
Just be aware that your floodlight is also doing other things besides lighting up an area.
First, it's ruining the night vision of anyone in the area. Then, along with that, it's creating super dark shadows.
To a burglar with even a little common sense, your flood lights will actually make it easier to stay concealed.
Re:let me translate that into slashdotese: (Score:4, Insightful)
Of course! Without it I am likely to be eaten by a grue.