Build a DIY Fluorescent Ring Light

Ring lights are cool. They produce a unique, near shadowless, slick, frontal illumination when used as a key light, and they’re an ideal on-axis fill. The only problem is, most ring lights are pretty darn expensive. So why not save a few bucks and build your own ring light. Rather than making a strobe version, though, we’re going to use a circline fluorescent bulb, which means this constant source can not only be used for still photography, but for video recording, too. Here’s how to build my faux-flo ring light.

Let me start by saying if you’re uncomfortable working with electrical components, this project isn’t for you. And if you’re mechanically inclined enough to try this, be very careful. Never work with live electricity, and definitely don’t modify or take apart the ballast that regulates the voltage delivered to the fluorescent tubes. In short, if you know what you’re doing, there’s nothing more difficult here than rewiring an electrical cord. But if you don’t know what you’re doing, you shouldn’t try this at home.

I was going to build a ring light from scratch, having decided on a circline fluorescent bulb because it’s already perfectly ring shaped. All it takes is the bulb and the associated ballast, and with a little basic wiring—and a cobbled together base to affix them—my ring light would be all ready to go. But then I noticed a few options in pre-assembled fluorescent light fixtures that contain all the necessary parts and then some, and in terms of cost, there was no premium over purchasing the parts independently. So instead of buying separate parts, I purchased a $39 round fluorescent bathroom fixture that I could chop up and customize as needed. The key before making this type of purchase is to determine that the circline bulb is large enough to put a lens through (six inches is plenty) and that the base is assembled in such a way as it would be easy to modify. If not, purchasing bulbs and ballast independently would be the way to go, and likely affixing them to a homemade plywood frame.

For my ring light fixture, the first step was to remove the ballast from the center of the base. It unscrewed easily with two screws, which I saved to remount the ballast in a later step. Having removed the ballast, I was essentially staring at a painted sheet metal ring with built-in clips for holding the circline fluorescent tubes. Perfect.

Using tin snips (or, if you’re so fortunately inclined, a power tool like a Dremel or a Rotozip) the next step is to cut a hole in the center of the fixture base. It’s metal, but the tin snips made quick work of it. I traced a roughly six-inch circle to make sure I didn’t end up cutting a wobbly, oblong opening. Next, I used a metal file to take the burrs and sharp parts off of the newly cut edge, and then I simply wrapped it in a layer of gaff tape to provide a bit of cushion on the relatively sharp edge.

Next I fitted the bulbs in place to determine the best place to drill a small opening for their wiring harnesses. That then dictated where the ballast should be mounted; in this case, on the left rear side of the ring light.

With the ballast in place, it was time to do the wiring. I connected the wiring harness to the tubes (it just clicks in place) and then wired a male household plug to the end of the ballast’s input wires. I wrapped them with electrical tape, and used the additional ground wire for the base to add a bit of stability by taking the tension off the connection. In generation 2.0 of this light, I’ll probably use a household extension cord to wire directly into the ballast, and then I can also add a simple inline switch for on-off purposes. This one simply uses that extension cord to plug in and turn on the light.

I knew from the beginning that I’d need a solution for mounting the ring light, but I didn’t know how simple, ultimately, the mount could be. I had expected to use a piece of metal bracket and drill it into the edge of the fixture, creating an out-of-proportion lollypop shape. It turned out, though, that a simple Manfrotto Superclamp was the perfect mount. I can tighten the jaws of the clap on the metal ring edge of the light, and use the baby stud to affix the whole rig to a c-stand. In my first tests that made it pretty easy to raise and lower the light to match my subject’s height. The first time I used it for an actual assignment—which I have done—I used the quarter-20 threads on the bottom of the Superclamp and mounted the ring light rig to the tripod head on my studio stand, so now it’s really easy to reposition the light as subjects change.

Notice that I haven’t mentioned the color temperature of the bulbs, which in this case was 5500k? I didn’t concern myself with color temperature, particularly because I knew I wouldn’t be using this light in conjunction with other sources, so I could simply dial in a custom white balance as needed. That’s what I’ve done with every shoot, and the ring light has worked well for several portrait subjects. I haven’t been bothered by the traditional fluorescent “green spike,” but I’m confident that if I do notice it creeping into shots that I can dial back the green channel in my image files when I’m processing the RAW files in Lightroom and Photoshop. Nor have I noticed any flicker of the tubes, though serious testing with video will determine if it’s an issue. I don’t expect it.

Also, I was worried that the light’s output—55 watt equivalent, according to the packaging—would be too dim to be particularly useful. In fact, the light output is brighter than anticipated, and the wide-open aperture creates a distinctive shallow depth of field look that I’m not used to getting in my studio photographs. It’s all part of the package, and from the first test shots I made with this DIY ring light, I’ve been really impressed. I can’t wait to give it a try for more than a test video. Its distinctive illumination is sure to make for an interesting video.

One thought on “Build a DIY Fluorescent Ring Light

Leave a Comment