The Construction of the Pin Hole Camera & the pin point problem

The second day ended with each one of us making a pin hole camera for ourselves. The steps were simple. The materials used were:

1. Black paper - This will be used for the body of the camera, so the thicker the better.

2. A piece of Gateway - To be used as the screen on which the image is to be seen.

3. Cello Tape

4. Scissors

5. Pencils

6. A pin

Steps:

1. Cut out a rectangular piece of the black paper. It is supposed to be rolled into a cylinder. The length of it should be something that you are comfortable with. Mine was about a feet long. The diameter was around two inches. One can use any readily available cylinder of similar dimensions.

2. Cover one end of the cylinder with a piece of the black paper, so that it completely seals off one end. Hold the sealed end against any bright background and see into the cylinder. You'll be able to see any light leaking in once you let your eyes adjust to the darkness.

3. Cover the other end with a piece of the gateway. Make sure that the surface stays as smooth and flat as possible.

4. On the gateway end of it, wrap another piece of the black paper. Place it in a conical manner. This will act as the eye piece.

Feel free to make it as fancy as you want.

The answers found and the questions raised were that the human eye, the lens in it to be more precise, when completely relaxed it can focus on objects 15 feet away, or more. Hmm. That is what my eyes can't do. I am near sighted. For objects closer than that, the curvature of the lens, controlled by tiny muscles around it changes. With some help from the brain, the images are accommodated on the retina. Retina is the screen at the back of the eye that catches the images and sends it to the brain.

So, if the eye has a variable focal length, how come the angle of view does not change, just as it does in case of lenses for the camera?

Whenever one goes through a corrective surgery for the eye, as in case of cataracts, the lens is replaced. But the person needs to continue wearing glasses. Because the difficulty in vision is due to the weak muscles that cannot change the curvature of the lens.

A lot of food for thought. But the day did not really start as good. The one down with fever came in  late. Just a minute after Mr. Tanmay Agarwal. The deterrent was the cancellation of the first session of the class. The second half started with the pent up grudges lurking in most of us. The one with fever has let us down more than once.

Mr. Tanmay pointed out its our fault.