American Buddhismâs numbers are booming. Published just over three years ago, an American Religious Identification Survey survey showed that from the years 1990 to 2000, Buddhism grew 170 percent in North America.
However, for a lens, a positive image distance implies that the image is located on the opposite side as the object. Virtual images are formed by concave lenses or by placing an object inside the focal length of a convex lens. The ray-tracing exercise is repeated for the case of a virtual image. In this case the virtual image is upright and shrunken. The same formula for the image and object distances used above applies again here.
1 Virtual images can be either upright or inverted. 2  Virtual images can be magnified in size, reduced in size or the same size as the object. 3  Virtual images can be formed by concave, convex and plane mirrors.  Virtual images are not real; thus you could never see them when sighting in a mirror.