D.I.Y. Dome Diffuser

February 6th, 2011 5 Comments

Off-camera flashes are a great way to enhance your photos. There are any number of great flash accessories from from companies like Honl Photo, LumQuest, and Gary Fong (links at the end of this article). The products they offer are very cool and allow you to take you flash technique to “the next level”, to use a cliche’d phrase. Unfortunately, you can spend a small fortune on various light-shaping tools to create the shot you’re going for. Here is my humble offering in the form of instructions to make your own dome diffuser. It actually does a nice job of evening out and softening the light. The best part is, it costs 35¢ for the plastic bowl with cover, and @ $5 for a can of white spray paint!

I picked up four 4″ diameter plastic bowls at my local Dollar Store for, er, a dollar…..so 35¢ each.

Four-inch plastic bowl.

The next step is to simply spray-paint the inside of the bowl with flat white spray paint. You want flat white to minimize reflections inside the bowl. I wasn’t able to totally eliminate reflections, even with flat white, but I gotta think flat is beter than glossy! I wound up giving my bowl 2 coats. This effectively stopped-down the light by around 2.5 to 3 stops.

Bowl after 2 coats of flat white paint……still pretty reflective!

Next, you need to cut a square opening in the lid the size of your flash head. I used and Exact-o Knife to cut the plastic lid. I wound up cutting diagonal slits in the corners so I didn’t have to worry about cutting the opening to the exact diameter of my flash head. It isn’t that easy to cut with a large degree of accuracy, so the slits are necessary in my opinion. They allow you to fit the lid over the flash head easily.

Lid after the opening for the flash head was cut….note the diagonal slits in the corners

That’s basically all there is to it! Below is a photo of the completed diffuser. It doesn’t look like much, but it actually works pretty well.

Viola!!

Below is a shot of my flash being fired with the diffuser in place. Note that the light is diffuse enough to eliminate lens flare, even though I shot directly into the light source.

Flash with diffuser.

Here is the same shot with the diffuser removed.

Flash without the diffuser.

How well does it work? See for yourself! I had to enlist the help of my favorite model to assist me in this demo. The first shot is of my model with the diffuser fitted over the flash head. Note the soft shadows being thrown behind her, and how little difference there is between shadows and midtones.

Shot with the diffuser.

Next is a shot with the diffuser removed. Besides the harsh shadows and wider contrast, the scene is about 2 to 3 stops BRIGHTER!

Shot without the diffuser……2.5 stops more light.

Just to make sure there’s no confusion here, since the non-diffused photo is so bright, I shot another one with the diffuser off and the flash stopped down 2.5 stops. Clearly, the contrast between shadow and directly lit areas is much greater. Compare it to the first shot, the one shot with the diffuser on the flash. Which one do you think is more pleasing?

Shot without the diffuser……stopped down 2.5 stops.

You might argue that the diffuser is flawed due to the light being stopped down so much. NAH!!! Just adjust your camera’s exposure…..you know….as in Exposure Compensation? Let me put it this way. Gary Fong makes a dome diffuser. It is no doubt a real nice product. It sells for $59.95. If you buy a warming attachment, add another $19.95. My diffuser costs 35¢ ($1 divided by 4 = @ 35¢ each), and if you pick up a set of Rosco “Strobist Collection” gels for a little more than $9, you can manipulate flash color in a variety of ways. So you decide. I made 4 of them, one for each of my flashes! What can I say?

Links to some websites that sell flash accessories:

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5 Responses

  1. [...] Gary Fong’s “Light Sphere” but I didn’t want to shell out $40 sight unseen. I found this DIY tutorial that turns a Tupperware container into a Light Sphere knock off. It works really darn well and if I [...]

  2. dave miga says:

    Nah! You all miss the point; simply flash BACKWARDS into a large white sheet of craft paper. Perfect, even lighting with just a tiny hint of soft shadow. Look at the experts with their fancy white umbrellas shooting their flash backwards into the umbrellas. And you only had to buy a sheet of white cardboard!

    • Gary Dates says:

      I’m afraid YOU missed the point. You don’t use a dome diffuser for the purpose that you describe. Bouncing off a white sheet of cardboard will direct the flash output to at most a 180 degree angle, with about 1 stop of loss in output.

      You use a dome diffuser to evenly distribute the flash output in a room that hopefully has white walls and ceiling. In this way, you effectively transform the walls and ceiling into giant softboxes. The end result being you get evenly distributed bounce plus the output from the diffuser itself. You can’t get that by bouncing off a sheet of white paper. And BTW, a bounce umbrella will direct the flash output much more efficiently than a piece of paper, so you have much more directional control. Plus, since the umbrella can concentrate the beam much better than a piece of paper, you get more output from the flash.

  3. JG says:

    umm… Fricken awesome!! it amazes me i didn’t think of this super simple idea. Thanks for sharing!!

  4. Ben says:

    How do you get $0.35? $1/4= $0.25 . . .

    Where did you buy your paint?

    Good tut. :)

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