DIY Ringflash

Tim KamppinenTim Kamppinen Registered Users Posts: 816 Major grins
edited March 3, 2009 in Accessories
NOTE: This was moved here by a mod, which is why it seems to start in the middle of a thread. Hope it's useful.
Grly wrote:
I really dig the post on these! Care to share your DIY ringflash setup?

Thanks! The following is copied and pasted from a post that I made about it on the Strobist forums:

Well, after tossing together a ringflash out of a plastic bowl, a tin can, and some aluminum foil, I decided that it was something I would want to be able to use whenever I had the whim. The problem was that the first one I made was pretty awkward to use as I had to either hold it with my left hand, or use the mounting bracket I made for it, which resulted in not being able to use the zoom and focus rings on my camera. There was also severe vignetting, basically a dark circle around my shot, if I shot at less than about 40 mm. The light was really cool though, so I set out to make a more practical and long-term solution. I was definitely inspired by a lot of the ringflashes that people on this forum had made, so none of this is very original. Here's the finished product:

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Diffusion material is a white sheet. The opening is large enough to shoot safely at about 20mm without any vignetting.

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It's constructed out of two mixing bowls, a saucepan cover, a tin bucket, cardboard, steel bars, 1/4-20 bolts, a white bedsheet, tinfoil, and a whole lot of hot glue. Then I spray painted it black so it didn't look quite so ghetto.

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I covered a small area on the inside with tinfoil. It was a small tin bucket that I used as a spacer between the two mixing bowls. The bowls themselves were stainless and already mirror-like.

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The camera bolts on to the mounting bracket with a 1/4-20 wing bolt. There's enough space between the ringflash housing and the camera to allow me full access to the zoom and focus rings on my lenses. The strip of material on the bracket is to add some extra grip so the camera won't rotate when shooting.

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It looks rather unwieldly, but with the camera securely bolted on it's much easier to handle than a flash mounted ring that you have to hold separately. There are plenty of "handles" to grab, such as the flash mount or the metal bracket that will allow the whole flash-camera unit to be balanced quite well. The whole thing with flashes weighs a little over five pounds, but when held with two hands it doesn't feel that heavy. It feels like a lot more when held with one hand, though, because it sticks out from the camera so far. The flashes are held in place by friction. The velcro on the heads helps make a tight seal. I don't worry at all about the bottom flash falling out; it's in there until I pull it out.

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Two sb28's at 1/4 power, f/7.1.

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Two sb28's at 1/4 power, f/20.

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Two sb28's at 1/4 power, f/32. The two dim spots are the points where the flashes enter the ring. I couldn't notice any variation due to this in test shots. Either way, the top and bottom of the ring (in portrait orientation) are evenly lit.

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One sb28 at 1/4 power, f/16 I think. One advantage of the two flash design is its versatility. I can use just one flash and get pretty good coverage, and have my other flashes free for something else (like rim lights). Or I can use two and get maximum power and evenness of coverage.

Here's an example shot using just the ringflash:

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In closing, I would just like to thank whoever invented the hot glue gun. Is there anything it can't do?

*Someone in the thread asked me for more info about construction, and this is what I posted in response:

I'm not going to do a step by step tutorial because A) it would take me a long time, B) I don't have pics to go along with it and it could get confusing, and C) I've found that the best way to build DIY stuff is to look at what other people have done and mix and match the different elements into something that works for you, rather than following step by step instructions. I will explain what I did, but I can't promise that it will be "step by step".

I picked up the large stainless mixing bowl at a local hardware/appliance store for $9. It's the only place I found anything like it, and I checked walmart, the dollar store, and everywhere in between. I have found them online since then however. Just search for "stainless mixing bowl" and you'll find some stores selling them. It's pretty big (about 16" I think) which I wanted both for a softer light source and to give plenty of room around the lens to eliminate vignetting and give me access to the lens rings.

The interior bowl I found in my kitchen. It's maybe 9" in diameter. There is a piece of a tin bucket connecting the two. This bucket at one point held a slim-jim type product made of mechanically separated chicken. It was a display bucket for the product in the store. I found it in a dumpster while digging for expired chips (Don't judge me! They're still good... It's right outside the frito-lay warehouse...) and it sat in my garage for a year and a half until I cut it up with tin snips and used it for this. I cut a ring out of it and made slits around the top edge. I folded these down, making tabs that I used to glue the bucket to the inside of the smaller mixing bowl after I cut a hole out of the bottom of it. The point of the bucket was that I needed a smaller central tube to allow the light from the flashes to get around the edges of the ringflash. They were being blocked by the wide bottom of the inner mixing bowl. I didn't use just the bucket for the central ring because it was too narrow and would have resulted in vignetting at wide focal lengths. A large metal funnel could be cut up to serve the same purpose without using two separate parts. If I had one on hand I probably would have done that.

I could have just glued the bucket/bowl unit to the larger mixing bowl, but I cut the hole to big in the large bowl so the edges didn't line up (I was making this up as I went, and didn't always think far enough ahead.) So, I needed some flat surface to cut a hole in, mount outer bowl to, and then mount the bucket to as well. The best I could come up with was a saucepan lid that I found in my kitchen, in a drawer above where the mixing bowl was. Again, this is a totally unnecessary part if you plan carefully, but I screwed up and didn't want to start over spend the extra time trying to find a better suited part to use. I'm impatient.

I cut two relatively flash-head sized holes on either side of the large mixing bowl, and made the flash mounts out of cardboard and hot glue. I attached them to the outer bowl with hot glue as well (the whole thing is held together by hot glue. It sets very quickly and is quite strong if you use enough. I sometimes layer it like welding beads.) I made them very tight on the flash heads so that friction would be enough to hold them in place.

The mounting bracket for the camera was made from a piece of angle steel that I got at the hardware store. I cut it to the length of the bottom of my camera and then drilled a hole in it for the mounting screw. I realized that since I wanted to use a thumb screw to make things easier, I would need to cut a section out to allow my fingers room to turn the screw when mounting the camera. I cut two slits and then beat the hell out of the middle section with a hammer on a vise until it was sticking out far enough to cut off with the hacksaw. The whole thing got sort of bent out of shape when doing this so I had to pound it back with the hammer to flatten it out again. I drilled two holes in the each side of the vertical part to mount the arms to.

To make the arms, I had to figure out how far the camera needed to be from the ring so that I could still access the lens rings and yet not get vignetting. This was trial and error, propping the whole thing up with various objects and looking through the viewfinder, moving it back and forth. Once I found a good distance I measured it and marked an appropriate length on my steel bar (1/8 steel I think) and cut two of these out. I bent them at about 45 degrees at the ends and mounted them to the camera bracket with some bolts. I mounted them this way so the torque of the ringflash unit wouldn't cause them to sag and bend out of shape. Once I had them sticking out at 45 degree angles I twisted and bent the arms, using my bench vise combined with my raw brute strength (actually they are pretty easy to bend). I would bend them slightly, then check to see how they lined up with the bowl, then make some adjustments, until I had 2 inch sections of each arm on the end that laid flat on the surface of the bowl. I then drilled two 1/4" holes in these sections and drilled corresponding holes in the outer mixing bowl. I mounted the arms to the bowl with 1/4-20 bolts and nuts.

For the diffusion screen, put the unit down on a white sheet and marked a circle about 1 inch or so larger all the way around it and cut it out. With the bowl laying centered on this circle, I attached the screen with hot glue. I put a drop of glue on the back of the lip that ran around the bowl, then pressed the sheet down onto it. Then I put another drop directly across from the first one and glued the sheet on that side, being sure to pull it taut first. Then I did this again so I had the sheet glued in 4 places 90 degrees apart. I kept going around, back and forth, crisscrossing until the there was a drop of glue every quarter inch or so and the screen was stretched tight over the front of the ringflash. Be prepared to burn yourself a few times doing this; the glue really is hot!

I flipped it over and carefully cut out the center part of the screen, leaving enough to glue down. I then glued this down to the inside of the inner bowl in the same way, pulling it tight because after cutting out the circle it goes slack.

The final step was painting it. I spend a few minutes sanding the metal surfaces so it would stick better and then put maybe 5 coats of black spray paint on it. I used light coats and let them dry for 15-20 minutes before applying the next one. Painting the inner ring was the hardest part. I cut a piece of cardboard with a hole in it exactly the size of the inner bowl to put over the diffusion screen and protect it from the paint. I then sprayed through the hole (I had to hold it down with my hand to make sure no paint got around the cardboard). If you look closely there was some minor overspray but it isn't very noticeable and doesn't affect the output. I also put a piece of masking tape over the grippy material on the camera bracket so it wouldn't be painted and then get black paint all over the bottom of my camera every time I used it. BTW, that was cut from some sort of very dense foam beverage coaster that I found in a kitchen drawer.

Anyway, that's more or less how I made it. I hope this is useful to you guys. The important thing isn't exactly how I made it, but how you can incorporate the ideas into your own design. Go make one that's better than mine! (You can start by cutting down the big bolts that stick out of it when you're done... I'm lazy)

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WOW that's a long post... but there you go. That's my ringflash. Hope this can provide some inspiration/ideas to all you DIYers out there!

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