iPhone Magnifying Camera Mod

Step 2 Making Measurements and Marking

   First, you need to find the center point on the jar lid and mark it.  Next, choose where you want to attach the suction cup to your phone.  Measure from that point to the centerpoint of your camera lens.  You want to be fairly precise.  This will be the radius (on the iphone 3gs it is 1 1/8" from the center of the apple) for the circle that you will scribe on the lid with the compass.  Mark your lens positions centered on the arc of the circle.  Remember to make a mark for an empty hole for taking regular pictures and place your lenses in ascending order of magnification.  Find the diameters of the lenses and the "mushroom" part of the suction cup.