Hello and welcome to the workshop. Please click the next button!

Activity 1: Capturing images

If you have followed the instructions from the previous page, you should have a bottle which can be placed over your phone camera, or a phone wrapped in clingfilm.

  1. Practice positioning water drops over your camera, either in the bottle, or on the cling film. Try to ensure that the water drop covers the whole camera.
  2. Once you are happy with the water drop, take an object you want to take a picture of (e.g. a leaf) and move the object back and forth until you find a distance which gives you the clearest image.
  3. Now try making smaller water beads. Again, move your object back and forth until you get the clearest image.
  4. Did the size of the water bead affect the image resolution? Did the minimum focus distance change when you changed the size of the water bead?

Note: For clearer images, you can use a second device as a torch to create a backlight by holding it above the object you are taking a picture of.

Activity 2: Sugar water vs Water

We can change the refractive index of the water by adding different substances to the water:

  1. In a glass mix some sugar into the water
  2. Repeat the drop experiment with pure water, and then with the sugary water
  3. How did adding the sugar to the water change the image? Did the images come into focus closer, or further away?

Activity 3: Water vs Oil

Different materials have different refractive index, meaning that if we use a different liquid for the droplets, we will change how much the light refracts, which should change the minimum focus distance.

  1. Repeat the experiment, this time using vegetable oil. If you are using clingfilm to cover your phone, be careful that your speaker and headphone jack are covered.
  2. Do you get clearer or more blurry images than with water? Do you have to hold your objects closer to or further from the drop to get the image as clear as possible?