needingtoknow said:Doesn't this contradict the definition of focal length which states that it has to be half of the radii of curvature?
The radii of curvature determine the shape of a lens and the amount of bending that occurs when light passes through it. A lens with a smaller radius of curvature will have a more curved shape, while a larger radius of curvature will result in a flatter lens.
The index of refraction determines how much a material can bend light. A higher index of refraction means that light will bend more when passing through the lens. This can affect the focal length and overall performance of the lens.
Yes, the index of refraction also plays a crucial role in image formation. Even if two lenses have the same curvature, if they have different indexes, they will bend light differently, resulting in different images.
The focal length of a lens can be calculated using the lensmaker's formula: 1/f = (n-1)(1/R1 - 1/R2), where f is the focal length, n is the index of refraction, and R1 and R2 are the radii of curvature of the two surfaces of the lens.
Yes, it is possible for two lenses with different indexes to have the same focal length if the combination of their radii of curvature and indexes of refraction results in the same value when using the lensmaker's formula. However, the shape and thickness of the lenses will likely be different.