Talk:Fresnel number

Physics Stub‑class Mid‑importance

	Physics portal This article is within the scope of WikiProject Physics, a collaborative effort to improve the coverage of Physics on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.PhysicsWikipedia:WikiProject PhysicsTemplate:WikiProject Physicsphysics
Stub	This article has been rated as Stub-class on Wikipedia's content assessment scale.
Mid	This article has been rated as Mid-importance on the project's importance scale.

Fresnel diffraction at F>1??

On the page on diffraction, it says that fresnel diffraction is the more general case, which leads me to think that there is no F at which fresnel diffraction is more or less accurate. In other words, I'm saying fresnel diffraction can be used when F is anything, not just greater than one. Is this right? Fresheneesz 05:44, 20 March 2006 (UTC)[reply]

Nevermind.. Fresnel diffraction should be used when F is largeish. But this leaves out a bit of fresnel numbers. What if your F is .98 ? what then? Is there more accurate and general ways of determining diffraction? Fresheneesz 05:50, 20 March 2006 (UTC)[reply]

reply: For large L then the case will be Fraunhofer. Therefore Fraunhofer is valid for values of F less than 1.

Fresnel number definition

As far as I know, the given definition of Fresnel number is valid for the radius and not the diameter of the diffracting aperture. For the diameter you will have : F=(D/2)^2/(lambda*R