Photograph a hidden object. It must be clear what object is hidden. Sounds impossible to you? You can use the shadows, reflections and so to make clear what object you (didn't) photograph. Just a shadow, reflection... isn't enough, the hidden object has to be in the frame while you made the photo but must be hidden behind something else.
In other words: you place object A behind object B, which makes object A hidden, with that object A becomes the main object of this contest which you have to show us by means of a shadow, reflection or any other indirect means.
This contest is open for all levels. This contest is in finished. Check out the winners below!