I will apologize upfront for asking a question that has been asked before. I really hate to do things like this, but so far I haven't been able to come to a conclusion on the difference between a Fresnel and just plain GG? I believe the Fresnel gives a sharper image, but would also require the use of a condenser? Is this right? Sorry. I'm just trying to get the best high quality GG and I think understanding this difference would be helpful.

A "fresnel" is actually a type of lens. When referring to a "fresnel" ground glass, you are essentially referring to a ground glass focusing screen with a lens on one side that condenses light. No, you do not use another condenser in conjunction with a fresnel ground glass, that's sort of redundant.

The Fresnel lens was named after its inventor, French physicist Augustin-Jean Fresnel. Fresnel is actually pronounced "fernel."

That's what you get from being a techie in high school :)

Thanks Ben. That makes much more sense now. From what I have heard from other sources, a commercial groundglass will give you a brighter center with more light falloff as you approach the edges, but a Fresnel will be illuminated evenly across the entire surface. Your thoughts on this? I'm just trying to determine the best thing to use as a GG.

On another board this morning someone mentioned using the Canon Ee-A or Ee-S focusing screens. Both look good, and seem more available than the Nikon D screens. I couldn't find anything about these screens on this board though. If anyone has experience with either of these I'd like to hear it.

Fresnel is actually pronounced "fernel."

That's what you get from being a techie in high school :)

Actually it's pronounced "frah-NEL." That's what you get from speaking French. :)

Look at the illustrations at this page and you'll understand exactly what it is

http://en.wikipedia.org/wiki/Fresnel_lens

I have a Beattie gg, which is a Fresnel, and it's very evenly illuminated. Probably one of the brightest groundglasses you can buy. It's very expensive though.