We all have something or the other to hide, don’t we? Physicists from University of Rochester were well aware of that and went on to create a cloaking device that serves that purpose. However, that’s not even the best part about it; you can create one for yourself from the comfort of your home for as low as $100! As far as names go, this one is called the Rochester cloak.


Speaking of the equipment, you merely require a total of four lenses and an optics bench that would hold them in one position. When the lenses are appropriately aligned , the light bends around the target placed in between. This hides the target from plain sight. The rudimentary knowledge of lenses explains this concept. Basically, lenses can bend light rays. When a convex lens is used, it bends light rays in a way that they focus onto one point known as the focal point. The light rays would then converge to create a magnified image. The strength of this magnified image is dependent upon the focal length which is the distance between the focal point and center of the lens. The lesser this distance is, the greater the lens’s magnifying power.

With that lesson on lenses in mind, you are all set to make yourself a Rochester cloak. Follow the steps and surprise yourself:

  1. Get a couple of sets of two lenses, each bearing a different focal length from the other. This should mean you have a total of four lenses that will set you back by only about $30.
  2. Separate two lenses with different focal lengths by the sum of their focal lengths using an optics bench. For instance, if one lens bears a focal length of 3 inches while the other has 5 inches, separate the two by 8 inches (3+5).
  3. Repeat the process with the two other lenses.
  4. To finish off, you must know how far you will separate the two sets. This will challenge your math skills but here is an example considering the same calculations used in the second step: D=[2(5)(3+5)]/(5-3)=12 inches.

Rochester cloak hiding device

Lens diagram

If you have any issues understanding the equations, simply head to the official website of University of Rochester. You can view complete equations along with diagrams to assist you in the matter. This one might as well come in handy for you.