Why are images formed by a pinhole camera inverted?
To form an image, light has to bounce off an object, travel towards the lens (or pinhole in this case), and continue on to the back of the camera where the image is formed. Now keep in mind that light always travels in straight lines. So think of it this way (it might help to draw a picture of this using lines for the light rays): Let’s say you want to take a picture of Abraham Lincoln with your pinhole camera. He is standing in front of you. Light bounces off his hat towards your pinhole. Draw a straight line from his hat to the pinhole. Light bounces off his feet towards your pinhole. Draw another line from his feet to the pinhole. You should have a simple drawing of a triangle. But now remember that the light will continue on inside the camera from the pinhole to the back of the camera. That is where the film would be located. So now extend your lines inside the camera from the pinhole to the back wall of the camera. You will notice that the light ray that started out at his hat is
