what is pin hole cemera

pin hole cemera are ancient cemera which have a pin hole in front and the image form is inverted.

http://www.google.com/search?q=pinhole+camera&biw=1868&bih=933&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwiu-8Keq4LOAhWQuB4KHTSOBNcQsAQIWg

A pinhole camera is a simple optical device used to form an image without a lens. It consists of a light-proof box or container with a small hole on one side, which allows light to enter. The light passing through the pinhole projects an inverted image onto a screen or photographic film placed on the opposite side.

To understand how a pinhole camera works, you can try simulating it with a few materials:

1. Get a shoebox or any similar container with a removable lid.
2. Paint the inside of the box black to make it light-proof.
3. Create a small hole in the center of one side of the box. You can use a needle or pin to make a very tiny hole.
4. Cut a piece of tracing paper or wax paper to fit the opposite side of the box, where the image will be projected.
5. Cover the hole with a small piece of aluminum foil and poke a tiny hole in it using the needle or pin.
6. Replace the lid of the box.
7. In a dark room, shine a light source (like a lamp) towards an object or scene. The light will pass through the pinhole, forming an inverted image on the tracing paper inside the box.

The pinhole camera works based on the principles of optics. When light passes through the pinhole, it spreads out and forms an image due to the rectilinear propagation of light rays. The smaller the pinhole, the sharper the image, but the longer the exposure time required.

Now you have a basic understanding of how a pinhole camera functions.