I have a graphic view that I would like to replace the ground glass. Is there a difference between the graphic view gg and other gg like the crown or even calumet? What should the thickness be?

I wasn't sure, so I pulled out my GVII and digital mic. My GG measures .06" or 1.54mm. Total thickness with Ektalite is .142" and 3.6mm.
I'm not sure the GG is the same as a Speed/Crown, but I believe it is. And I wouldn't worry about the second decimal place on the mm's. I got varying readings... Just a plain 1.5mm will do nicely.
I wish I could help as far as Calumet or Toyo or any other one. I do think I replaced one with a Toyo, but that could have been a freznel, or a Calumet, or who remembers after a while?
The only important thing about the GG is that it fits in the hole! After all, it's only the frosted/etched surface that counts and that will always be in the same position no matter how thick the clear glass is behind it. Although there would be a limited variance since it does have to fit with the hold-downs and hood. Too thick and the hood won't fit!
I'm sure someone else will know if the Calumet or Toyo GG is the same...

Quote:

On 2003-05-22 20:25, RichS wrote: I wasn't sure, so I pulled out my GVII and digital mic. My GG measures .06" or 1.54mm. Total thickness with Ektalite is .142" and 3.6mm. I'm not sure the GG is the same as a Speed/Crown, but I believe it is. And I wouldn't worry about the second decimal place on the mm's. I got varying readings... Just a plain 1.5mm will do nicely. I wish I could help as far as Calumet or Toyo or any other one. I do think I replaced one with a Toyo, but that could have been a freznel, or a Calumet, or who remembers after a while? The only important thing about the GG is that it fits in the hole! After all, it's only the frosted/etched surface that counts and that will always be in the same position no matter how thick the clear glass is behind it. Although there would be a limited variance since it does have to fit with the hold-downs and hood. Too thick and the hood won't fit! I'm sure someone else will know if the Calumet or Toyo GG is the same...

Thickness shouldn't matter. The gg goes in the focusing panel with the ground side towards the lens. The image is formed on the ground side, and that's what we focus on.

However, the ground side has to be the same distance from the lens as the film. If a fresnel was put in front of the gg in a focusing panel not designed to hold the fresnel, then the ground glass will sit in slightly the wrong place and focusing on the gg won't quite work. Fred Lustig gave me a lecture about this two weeks ago.

Cheers,

Dan