Crop Circles

In some photos people notice that have some stamps similar to dust.
The first time people saw these were in cemeteries in the 90's, some American ghost-hunters though that these marks were the souls of the dead people.
These marks are known as crop circles.
Incredibly these marks have different shapes, colors and when flying above farms, people say they make drawings on the ground.
The people who think these crop circles are real, they say that if you look with much attention, on them you see a human face.
Scientists made anti-crop circle-cams which when tested, proving that the crop circles are camera defects.
But people still believe that crop circles are real.