Answer Happy

Pinhole pattern and lens O Turn off your light, poke more holes in your card and use it to cover up a lens as shown here so that light from the bulb will pass through both the holes and the lens before it strikes the screen. O O O O O o Prediction: What will you see on the screen when the light is turned on? What if the screen is moved closer? What if the screen is moved farther away? Try it. Move the screen closer and farther away. What do you see? What happens when you cover up the holes one at a time?

If you poked even more holes in the card, what would you see? If the card had too many holes in it, it wouldn't be there. Use the idea of a collection of holes edge-to-edge across the lens to describe what you would see as the screen were moved closer and farther away. What would all the patterns look like when the screen wasn't at the focus position? How do lenses form images?