The
Canon Off Camera Shoe Cord #2 (OCSC2) is a great way to get E-TTL flashes away from the camera shoe, and can make for much more dramatic or flattering images. The problem is that the cord is only 2 feet long; enough for a flash bracket, but not long enough to get the flash truly off camera. I needed a cheap and easy way to extend it.
[notebox]
I do feel that I need to throw one caveat out. This worked for me, it may not for you. If you’re not willing to risk the cable, your camera, or flash, please don’t try this.[/notebox]

One solution is the
Canon ST-E2 wireless transmitter. But, at over $200 this was a little overkill for what I wanted.
What I had done previously was to stack 3 OCSC2 cables together. While this got the length up to 6 feet, it was hacky. More importantly, I worried that it was putting extra stress on the connections.
So, I went out in search for a way to extend the cable in a way that was clean, and almost as importantly, cheap.
The Canon cable is a 5 lead with a ground, so we need a cable that is a close to that as possible. A trip to Lowes brought back a 7 lead wire intended for thermostats. Ultimately, this was the wrong cabling. The flash would fire, but it was at full strength every time. Back to the drawing board…
Leaning back in my chair with my keyboard in my lap it hit me. A keyboard cable has six wires, and they’re usually coiled like the OCSC2. A run to Office Depot and I came back with two 6 foot mini-din keyboard extension cables. They’re not coiled, but will serve the purpose. I was set to go again for $19.98 plus tax.
The first step is to get our tools and parts together. We need: wire cutter, wire strippers, x-acto knife, electrical tape, Canon OCSC2, and 2 keyboard extension cables. One keyboard cable will be cut and one will be used as the extension.
Cutting the CordThe first step is the most unnerving. You have to cut a perfectly good $60 cable in half. Fortunately, I have 3 of these – two camera rigs plus a backup. But it still was a little tough to bring myself to cut it in half. I cut it as close to in half as I could without actually measuring.
You will then need to strip off about 2 inches of the black coating to expose the individual wires. Inside you will see red, white, blue, green, and black wires surrounded by an uncoated stranded wire. Unwrap the uncoated wire and twist it together. Strip about half an inch off each of the individual wires.
Cutting the Cord 2Next we need to cut the keyboard cable. Cut about 6 inches away from each connector and strip off 2 inches of the coating. The cable I had was able to be stripped with a 10-guage stripper. Inside, wrapped in a metallic shielding which you’ll remove are red, purple, yellow, green, black, and orange wires; plus an uncoated one. Strip half an inch off each of these except the orange, which will not be used.
Making the connectionNow we connect the wires to each other. I connected red to red, green to green, black to black, yellow to white, purple to blue, and uncoated to uncoated. As long as you’re consistent between the two sides, you should be able to connect however you want, but I tried to make it easy.
Twist the connections together tightly and wrap with a small piece of electrical tape. You could also solder or use screw connections, but I was going for easy. You’ll wind up with something that looks like this.

Repeat with the other end and connect the two keyboard ends together to make yourself a short cable. Right now it’s only about as long as the original OCSC2, but we’ll fix that in a minute.
Trying it outI plugged the cable in between an Elan 7 and 420ex to see if it would work. Ultimately it’ll be used on a 10d and 550ex, but if a camera or flash is going to blow out I’d prefer it be the (relatively) cheaper one.

And, it worked. The autofocus assist light came on and the flash fired. So moving to the 10d, the following is the first image. While not a great example of off-camera lighting, it is well exposed.

All that is left is to clean up the loose ends. Wrap the loose wires in electrical tape to clean it up and keep them from getting snagged and you’ll wind up with the finished product.
ConclusionIt works, and that’s the important thing. Although, it’s not quite as neat as I’d like. I've stacked two keyboard cables together for about 12 feet of length and it worked, although I've read in other places that much more than that and the flash starts to act up.
Room for Improvement?I may go back and untape the ends and redo it with heat shrink tubing to clean it up a little. It won’t make it function any differently, but it’ll look a little better.
If you’re so inclined, you could also open up the two ends and solder the wiring directly into the shoes. I’ll warn you that it’s a pretty small area, which is why I didn’t try. But, if you’re good with a soldering iron, you could make a pretty slick version. Let me know if you do, I’d like to see it.