Where does the ray hit the image plane?

The point where the ray hits the image plane depends on the specific setup of the optical system. Here are the general steps to determine it:

1. Identify the optical system: The optical system could be a camera, a human eye, a telescope, etc. Each of these systems has a different way of bending light rays and focusing them onto an image plane.

2. Locate the object: The object is the source of the light rays. It could be a physical object, a distant star, a microscopic specimen, etc.

3. Trace the ray: Draw a straight line from the object to the lens or mirror of the optical system. This line represents the path of the light ray.

4. Apply the lens/mirror equation: This equation relates the object distance (distance from the object to the lens/mirror), the image distance (distance from the lens/mirror to the image plane), and the focal length of the lens/mirror. You can use this equation to calculate the image distance.

5. Find the intersection point: The image distance tells you how far behind the lens/mirror the image plane is. The point where the ray hits the image plane is the intersection of the ray and the image plane.

Remember, in a real optical system, light rays from each point on the object spread out in all directions, and the lens/mirror focuses these rays back to a single point on the image plane. So, the image is a collection of these points, each corresponding to a point on the object.