What causes gradual lighting up of street illumination on long streets?
Q. When they light up street illumination in cities like New York, it seems to be progressive and not all the lights are on at the same time. It seems like a "flow of power" turning them on gradually as it progresses through the wires. But I am quite convinced that it is just for effect or rather to protect the power network and not because electric current works like that. I think that physicaly when you connect power supply to a wire all the lights connected to that wire light up at the same time no matter how long the wire is. Is there any related material online describing this problematics of lighting up big cities?
Asked by mr_fish04 - Tue Sep 11 06:10:40 2007 - - 3 Answers - 0 Comments

A. The answer is pretty simple. Sometimes an electrical contractor will install a photocell to control an entire electrical circuit. In this situation, all lighting will switch on and off at precisely the same time. In the scenario you are talking about, the electrical contractor with the lowest bid got the job. Instead of installing a photocell for the entire circuit, he went the cheaper route and bought light fixtures, each with its own integral photocell installed from the factory. In this case, each light switches on and off independently from the other fixtures on the same circuit. As shadowing progresses down a street, the lights will start coming on, one after another, and it appears that it is for "effect". You can rest assured that… [cont.]
Answered by prime8 - Wed Sep 12 09:03:03 2007

How many watts of lighting do I need over a dining table?
Q. I foolishly bought a pendant lamp with only a 100 watt halogen light bulb for my dining area. Now that I've decided to replace it with a bigger chandalier, how many watts of light should I be looking at? I do have a Lutron dimmer, so it'll be adjustable. Is total wattage even what I should be looking at? Is there some other measurement to consider? Because my dining room has a sloping roof, I can really only do a single chandalier or pendant lamp. A single pendant lamp will never be bright enough -- so that's out. Most chandaliers tend to have lamp shades that focus upwards, whereas I know lighting for a dining table should mostly focus downwards -- to draw people into the dining area. What are my options? For what it's worth, I… [cont.]
Asked by Ferg2k - Sat Apr 8 23:03:50 2006 - - 5 Answers - 0 Comments

A. Wattage definitely is what we think of when we think of how bright a light bulb is... but that generally really is meant to indicate how much electricity the unit is converting to another form of energy (light/heat). You could use a 9 Watt fluorescent screw-in bulb that has the same brightness as a 40 Watt incandescent bulb. Anyway, what you need is, as you said, something that DOES direct light down to your eating surface... not up onto your cavernous ceiling. I actually believe that there is a pretty decent selection of chandeliers out there with lamp covers that direct light down... you just might have to shop around a bit. Have you considered a small track-lighting installation that would allow you to hang, say, three pendant… [cont.]
Answered by A Designer - Sun Apr 9 01:17:04 2006

What type of portable lighting equipment should I invest in?
Q. I am a freelance photographer and am ready to purchase some lighting equipment. I have been using natures light, but in the winter I do more indoor shots. However, I travel to the clients homes, so I need something portable.
Asked by Crystal N - Sat Jan 12 20:35:08 2008 - - 3 Answers - 0 Comments

A. I do portrait photography on location and use Photogenic for my main lights and Bowens for my backlights. They are pricey but worth it. They last a long time, at least for me. You should get a padded case to keep them safe given you are traveling with them. You ll need a couple light stands. A soft box or umbrella should be used to diffuse the light in order to get a nice and evenly lit portrait like you might get on an overcast day using available outdoor light. You'll need to be sure you have a power source and extension cords unless you plan to use a portable battery.
Answered by Studio B - Sat Jan 12 20:52:12 2008