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.
In contrast, a real image is one that is formed when the outgoing rays from a point converge at a real location. Real images can be projected onto a diffuse reflecting screen, but a screen is not necessary for the image to form. 1  A plane mirror forms a virtual image positioned behind the mirror. 2  Although the rays of light seem to come from behind the mirror, light from the source only exists in front of the mirror.