Fresnel Lens Limitation


In the part of aberration of lens in convex lens, Fresnel lens is used to solve the problem. But it is said that Fresnel lens is of 'poor optical quality'. What does it mean? Isn't it converge light back to focus and sharp image can be formed? Or is it related to the 'rough surface' situation which we can't see the reflection clearly?ject?


The Fresnel lens avoids the spherical aberration problem but superimposes an image of the lens itself on the image, sort of the 'rough surface' situation you describe.