Difference between Real Image and Virtual Image
A mirror can form two types of images. These are namely real image and virtual image. Let us understand the basic difference between these two types of images. Let us suppose that the object serves as a point object. All the light rays are coming from a single point of the object. These light rays hit a single point on the mirror surface. The result is production of a real image of that object on the screen or any other detector. The more intense the rays coming from the object are, the higher is the intensity of the image on the screen.
On the other hand, if the light rays that arrive to our eyes appear to come from a real object but they are in fact not coming from the real object, a virtual image is formed. It commonly happens when light rays from an object hit a plane mirror and are reflected. The resultant reflected rays appear to come from that object but the apparent position of the object is not real. It seems to be present behind the mirror but it is actually present in front of the mirror.
The process of image formation follows the law of reflection. According to this law, the angle formed by incident light rays is equals to the angle of reflection. Let us understand the formation of real and virtual images. Let us assume that light rays coming from the object are being refracted. The pattern of refraction is in such a way that the refracted rays come together at a point on the image. For the purpose, the distance between object and lens should be greater than the focal length of the mirror. The converging lens forms a real image. These lenses are also known as convex lenses.
Let us assume that the light rays are coming from an object. These rays hit a point on the mirror and are refracted. The refraction pattern results in divergence of the refracted rays. If we track these rays in a straight line, they appear to be coming from the same lens surface as if this is the source not the refraction surface. The image is the virtual image. A virtual image is formed when the distance between the object and lens is far less than the focal length of the lens. The concave lenses are the diverging lenses and from a virtual image.
A real image can be seen on the screen while a virtual image cannot be seen at a screen. The reason is that there are no light rays coming at the focus of the virtual image which is a prerequisite to see an image on the screen. Both real and virtual images can be seen with our eyes. This is due to the fact that the eye lens forms a real image on our retina irrespective of the source of the light rays. The real image is always inverted while a virtual image is erect.