Instructions for DIY ringlight for the photo enthusiast who wants a professional look without the associated cost. This project costs about a 10th of the real deal and works reasonably well. All told it cost me just under $100 to assemble and about 3 hours of time. I basically followed the workup offered here (http://www.noestudios.com/photo/ringlight/) but I found that it lacked the details about wiring it up. I am a total newcomer to electrical wiring but I sought aid from an expert who looked over my work and proclaimed it good. As a disclaimer, working with electrcity is inherently dangerous and requires a healthy respect for those dangers. I in no way take responsibilty for your safety if you decide to do this project. 120v AC current is very painful AND potentially fatal if the current crosses your heart (see the totally valid criticism below in the comments for an explanation). The danger on this particular project is relatively low but you are dealing with voltage so BE CAREFUL.
Anyway, enough disclaimers, lets get down to it!

Step 1: The Materials

I already had a bunch of scrap plywood from other projects so thats 20 bucks I saved on this for a sheet of 1/2" birch ply. You don't have to use birch, as it is slightly more expensive than douglas fir or particle board but I like birch. it's pretty.
The first thing to do is cut out our circle from our sheet of ply. I measured out 36" up and down and drew the ring with a pencil on a piece of string tied to a nail at the center. I tried to make as close to perfect as possible but the shape is not really that important because it is on the other side of the camera and won't be seen by anyone other than your models. By having a 36" outer diameter I was able to put 12 sockets on there about 5 1/2" - 6" apart. The ring is 6 inches wide all the way around, giving it an inner diameter of 30". You can go smaller in size if you need to but I wanted a big opening to shoot thru so that I can get wide shots without having to crop out the ring in my images.
I cut thing ring in half so that it will collapse down to half size for easier storage. The sliding bolt locks are not ideal for locking it into to the open position and as of this posting I am still looking for a better solution.

Not pictured below:
-20 feet of 12 gauge wire, 10 black, 10 white. it is pretty cheap, maybe 30 cents a foot.
-12 100 watt bulbs, $5
-bag of electrical connection caps, $3
-box of 1" screws (for sockets)
-box of 5/8" screws (for hinges and bolt locks)

Tools Required:
-wire stripper
-electric drill
-screwdriver
-jigsaw

Step 2: Putting It Together

by far the most tedious and time consuming part of this process is wiring it all up. This was made all the more difficult by the fact that I selected 12 gauge wire, which is very rigid and inflexible. I chose 12 gauge because of the high wattage that this thing is going to be using. 1200 watts is no joke and 14 gauge wire is just not up to the task of running that kind of current for extended periods. You can put the workbox where ever you want, I kind of selected that spot randomly, to be honest.
Also, do yourself a favor and buy a pair of wire strippers. Really, they're like 8 bucks and they make this job so much easier. If you try to do this with a regular pair of pliers it will take you LITERALLY 3 times longer. Even if you never use them again it is worth it. I don't use mine much, more frequently they are used as a bottle opener. But NOT while I was doing the electrical wiring. Safety first, beer second.
Strip back your wires about 3/8th", then bend them into a 'U" shaped loop, slip it around the terminal post, and then bent the U onto it to secure it. Repeat 4X for every socket.
One word about the wiring; when you are screwing down the sockets onto the ring, make sure that the connection terminals are all oriented the same way. One screw is gold, the other silver. They are on opposing corners so just pick a way and make sure the rest look the same. Generally speaking the way that wiring is done is to connect the black to the gold and the white to the silver. Just remember: black gold, white lightning! I wish I had a better neumonic for you but hey, you work with what ya got.
not displayed: the hinges are on the backside. The sliding bolt locks are placed opposite them on this side.

Step 3: Junction Box Wiring

OK, the worst of it is over. Now you just have to wire up your switch. Pop open the smallest perforated area on the side of the junction box with a screwdriver, and put the cable clamp into place. Cut off the female end of the extension cord, stick your extension cord in and pull thru some slack. Carefully slice open the orange sheathing, taking care not to cut the wires underneath, and expose about 4 or 5 inches of the wire inside. Cut the green wire off (that is your ground, you don't need it for this), and expose about 3/8s of an inch of the copper wire inside the black and white wires. Bring the wires from the first socket into the box via the top opening (with cable clamp already in place) and twist the white ends together and then twist a cap onto them to connect them. Make sure that no copper is exposed outside of the cap. Take the black end of the extension cord and wrap it around the pole on your switch that is closer to the off position, then screw it down tight. Attach the black wire from the first socket to the on pole and tighten it down. Lastly, tighten down the screws on the cable clamp to secure all those wires.
OK, now we are ready to test the thing. Screw in your 100 watt bulbs, plug it in, use a piece of wood to switch it on. and....

Step 4: IT WORKS!!!!

if it doesn't, well... you screwed up somewhere. Unplug it and double-check your connections. This is a pretty simple circuit and it if isn't working it is probably due to a bad connection somewhere. If it does work, unplug it, attach your plate cover, do a little happy dance, and move onto the next step.

Step 5: Sealing the Terminals

Time to seal up all that dangerous exposed wiring. The liquid electrical tape dries quickly, seals effectively, and smells terrible. It is more vixcous than I expected and I made a bit of a mess dripping it all over the place. 3 coats should be enough.

Step 6: The Stand

I rigged up my light stand using 2 cheapo tripods, one I got for $10 at a yard sale and one I already owned. I wouldn't say this is the most effective way to get the rig up into the air and I would strongly suggest using lighting stands, which would be sturdier and would allow for greater range of height adjustment.
If you choose to do it this way though, I drilled two 1/2" holes opposite eachother and crazy glued recessed nuts into the holes. The recessed nuts have a flange on one side so that they can't fall out. All tripods and cameras use 1/4-20 (commonly called a quarter-twenty at the hardware store) mounts so any 1/4-20 bolt will fit any camera. I attached the tripod quick release mounts to the recessed nuts for easier removal.

Step 7: Crack a Beer and Play With Yer New Toy

Congratulations, now the fun of shooting professional portraiture in your home studio can begin. You will need to be fairly close to the lights to get a good effect because even with 1200 watts of light I had to shoot with my aperture all the way open at about 125 shutter speed. Due to this, my depth of field was incredibly narrow making some of the shots worthless. I would have gotten a higher percentage of them if someone else had been on the other end of the camera and I wasn't running back and forth using the timed shutter. Oh yeah, REMEMBER TO ADJUST WHITE BALANCE FOR TUNGSTEN!!! If you fail to do this all of your shots will have a reddish overcast.
Also, I shoot with non-automatic prime lenses which means I have to meter off camera and generally accept that not every shot will come out. This half length one was shot with a 50mm Pentax Asahi lens, the close up was shot with a 135mm SMC Takumar lens. You might not be able get this kind of sharpness with all zoom lenses. At least, probably not with the kit lens that comes with your camera. I know that I can't with mine but maybe it is different with yours. try it out and have some fun.
I hope this project was a good learning experience and that it allows you the freedom to shoot some pictures that will astound your friends and peers wih their professional look. Happy shooting!

you can see more examples at:
http://flickr.com/photos/macdawg/