The Thatcher effect or Illusion is where it becomes difficult to detect local feature changes in an upside down face. Despite identical changes being obvious in an upright face.
It is named after British former Prime Minister Margaret Thatcher on whose photograph the effect had been mostly famously demonstrated on. This was originally created by Peter Thompson in 1980.
My task was to find an image of a celebrity via the internet and test out the illusion by using photoshop. This involved cropping areas such as the lips and face and rotating them so they are upside down. A low opacity, soft edged eraser was then used to smoothen the outer unwanted areas of the image away.
Once satisfied I rotated the image 180 degrees to see if the illusion had been successful.