Security Lighting Tips
Don't Over Light - The number one rule of decorative lighting is an important rule in security lighting as well. It's easy to think that if a little light is secure, then lots of light will be even more secure. That's not the case. Over lighting can actually impede your ability to see an entire area. If you're outside and your eyes are adjusted to the dark, a brightly lit area can have a blinding effect. Once your eyes adjust to the bright light, you'll have trouble seeing in the dimmer areas. Over lighting can produce dramatic shadows as well, shadows where intruders can hide.
This doesn't mean you shouldn't use flood lights or spot lights at all. But it does mean that you should save the powerful ones for really large areas. A driveway doesn't need a 300 watt halogen bulb turning night into day.
Avoid Glare - Glare is a closely related problem to over lighting and has some of the same effects. Glare in the eye can temporarily blind intruders, but it can blind you as well. You'll spend valuable time blinking to get the spots out of your eyes. Look for lights with effective glare shields and diffusers to spread the light evenly without bright spots.
To avoid glare, stay away from standard 175 watt "security lights" and globes. Both these fixtures send bright light indiscriminately in all directions. This makes them more expensive to operate as well. For every bit of useable light they put out, they send five times as much up into the sky or out into the street. Consider instead a well shielded low pressure sodium lamp. Energy efficient and with no glare, this kind of lamp can provide excellent visibility.
Control Direction and Field - Remember to direct the light outward from your house. This gives you the advantage over the intruder. You can easily look outward along the line of the light, but it's difficult for him to tell what's going on inside.
However, you want to direct the light in a way that doesn't provide a danger for passing motorists. And again, you don't want to waste light by sending it up into the sky. A flood light with a good glare shield, installed under the eaves can provide the illumination you need.
Make sure as well, that the light is not extending its field beyond the perimeters of your yard. You don't want to bother your neighbors with light pollution through their bedroom window.
With a little experimentation, you can aim the lights and control their field of illumination so that the proper area is well lit without being over lit and without any glare.