Distance measuring and coordinating light strength


I am an art student and have no experience with the Arduino yet. Nevertheless as far as I understand it is exactly what I need to work on one of my projects: I am building a (photographic) lightbox which is to become brighter as the viewer approaches it. Once the viewer is too close, it will turn itself off. The size of the lightbox is slightly above an A4 size paper and it will probably rely on electricity from a socket. Could someone please give me some advice on which elements I need to create this work? I majored in Physics before I came to artschool, but that was a while ago and so I am a little rusty with these things.

Kindest regards

Well it sounds like one of those gadgets that will drive you mad but whatever.

Are the lights inside the light box florescent lights? If so you have little hope of controlling the brightness of them. If they are incandescent lights then you might be able to use a solid state relay with dimming capability.

I know that it is very difficult to dim florescent lights so I have decided not to use them. Because of the size of the lightbox I could use any type of light. I am considering either halogen or led because conventional lightbulbs cant be purchased here anymore.
But yes, I do realize that this project is not the simplest.

High power LED discussion & useful links