The Image Fulgurator is, roughly speaking, an analog photo camera “working in reverse”. The device enables one to project images on other people’s photographs! The following schematic illustrates quite nicely how this “projector” works:
[ schematic courtesy of Julius von Bismarck ]
The Image Fulgurator is a device for physically manipulating photographs. It intervenes when a photo is being taken, without the photographer being able to detect anything. The manipulation is only visible on the photo afterwards.
In principle, the Fulgurator can be used anywhere where there is another camera nearby that is being used with a flash. It operates via a kind of reactive flash projection that enables an image to be projected on an object exactly at the moment when someone else is photographing it. The intervention is unobtrusive because it takes only a few milliseconds. Every photo another photographer takes of an object at which the Fulgurator is also aimed is affected by the manipulation. Hence visual information can be smuggled unnoticed into the images of others.
The Image Fulgurator is equipped with a slave flash that is triggered whenever a master flash is fired. Note that if you do not use flash when taking photos, you do not risk getting your photos “fulgurated”. I would say that many people have reacted to this device in an overly negative manner. I believe that the Image Fulgurator is a good idea and that Julius deserves credit for his ingenuity.