I have seen interesting videos and protests of people using light to project protest messages on buildings.  These guys started me thinking about this, and it seemed intriguing, so I set about to see a simple way to try this. The easiest thing I found is the EZ Gobo, which is a battery powered single unit.  It's light, pretty cheap, and easy to use.  The battery can last up to five hours.  However, it's only 10 watts, so it doesn't throw a lot of light.  This is actually an advantage, though, because it doesn't throw enough heat to harm non-metal gobos.  But this is just an experiment anyway, so there's that.

You can make your own customized gobos, which are the black 26mm circular discs that block the light except for the design you designed into the gobo.  They can be made with transparency sheets and a printer for really cheap, or you can buy a professionally made metal one for about $40 or more (this one is metal).  Changing gobos is also easy.

This first photo is from a closed Publix store, so there wasn't much light around.  I think it looks pretty good.



This next series is to show that in general, though, where there is typical night time lighting at a strip mall, you have to be pretty close to the wall to have good visibility. 

But as I said, this is a cheap, low-powered experiment.


projection from 20 feet away

projection from 30 feet away

projection from 40 feet away

If I was to use this at a protest, I would make sure not to shine into any window or door.  I would consult local ordinances to see if in some strange way some sign ordinance might cover this or something.  And I would make sure not to shine it on passing pedestrians or vehicles.  But otherwise, all you're doing is shining a light on a wall.  Nothing permanent or damaging there.