Droplets Forming: Idea: An optimally diffusing reflector

Wednesday, December 8, 2010

Idea: An optimally diffusing reflector

In an unlikely twist of events, here's an actual idea, like I intended to be posting.

The problem

I have a consumer digital camera, but I hate the glare of the flash when I take an indoor photo at a family event. So I usually either find a bit of white paper or a spoon and hold it in front of the flash to bounce the flash off the ceiling or a wall behind me. This has its downsides; you look silly, you flash whoever's behind you, it's cumbersome (particularly when shooting vertically) and it doesn't work whenever there's a dark or far away wall or ceiling.

The concept

So I thought it would be good to have a little diffuser I could attach to my camera. But a little piece of plastic would waste a lot of the light by sending it out the sides, more so the larger the diffuser. And so that it actually improves the shot, I'd like the diffuser to be a reasonable size (A6?). So how about using 2 bounces? Firstly, a bounce in front of the flash to redirect it upwards, and then a second above the flash to bounce it forwards. If both of those were made of some kind of semi-diffusing reflector, like shiny paper, or had a bumpy surface like crinkled tin foil, then the light would be diffused without too much loss. I could also just use the first reflector to bounce of the wall or ceiling.

Optimizing the solution

What shape should the two reflectors be? If the first was concave it could focus the flash onto the second reflector, or even (via a paraboloid) create a fairly narrow beam. The second reflector would need to again diffuse the light to create the most diffuse source it could. So could we throw two surfaces of nodes and a light source into an optimising algorithm and see what answer it comes up with? The constraints would be to maximise diffuseness of the resulting light (so a given point in the field of view would be uniformly lit from as wide an angle as possible), minimise size, maximise the intensity within the field of view, etc.

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Quotes

"Books won't stay banned. They won't burn. Ideas won't go to jail. In the long run of history, the censor and the inquisitor have always lost. The only sure weapon against bad ideas is better ideas." ~ Alfred Whitney Griswold

"If at first the idea is not absurd, then there is no hope for it." ~ Albert Einstein

"We are told to remember the idea, not the man, because a man can fail. He can be taught, he can be killed and forgotten but, 400 years later, an idea can still change the world. I've witnessed first hand the power of ideas, I've seen people kill in the name of them, and die defending them...but you cannot kiss an idea, cannot touch it, or hold it...ideas do not bleed, they do not feel pain, they do not love." ~ Evey Hammond in V for Vendetta

" Ideas are somewhat like babies--they are born small, immature, and shapeless. They are promise rather than fulfillment. In the innovative company executives do not say, "This is a damn-fool idea." Instead they ask, "What would be needed to make this embryonic, half-baked, foolish idea into something that makes sense, that is an opportunity for us?" " ~ Peter Drucker, The Frontiers of Management (1986)