Suppose all the light rays originating at a point P on an object and heading off in some range of directions later meet and pass through another point X. Now suppose those same rays continue into your eye. Your eye cannot tell the difference between those rays and rays emanating from an object, like the original object, placed at X. If rays starting from other points near P also meet, at points somewhere near X, in a continuous mapping, then your eye will see a complete, though possibly distorted, object at X.andyrk said:
Images are formed when light rays from an object pass through a lens or reflect off a surface and converge at a point. This point is known as the focal point, and the image is formed at the focal point.
The lens plays a crucial role in the formation of images by refracting (bending) the light rays that pass through it. This refraction causes the light rays to converge or diverge, which ultimately determines the type and position of the image.
The distance between the object and the lens, known as the object distance, affects the size and position of the image. When the object distance is increased, the image becomes smaller and moves closer to the lens. Conversely, when the object distance is decreased, the image becomes larger and moves farther away from the lens.
A real image is formed when light rays actually converge at a point, and it can be projected onto a screen. On the other hand, a virtual image is formed when light rays appear to converge at a point, but they do not actually do so. Virtual images cannot be projected onto a screen.
The shape of the lens, specifically its curvature, determines how much the light rays are refracted. A convex lens, which is thicker in the middle, will refract light more than a concave lens, which is thinner in the middle. This difference in refraction will result in different types of images being formed.