Advice for new Groundglass / Frensel for Speed Graphic

[lambis]

I have a Speed Graphic Pacemaker that have a old groundglass and a frensel that i like to exhange with a better groundglass and eventually a new Frensel

I have read that those Speed graphics that come with a frensel, need to have always one otherwise the focus will be not correct. Is it true?
Anyone have a advice /experience what groundglass / frensel i could use?

[David Karp]

I have an old Crown Graphic with a Fresnel lens. When I first got it, the image on the GG was dim. I kept thinking I needed a new GG and/or Fresnel. One day I removed them, washed them off with lukewarm water and gentle soap, and replaced them. Voila, everything was nice and bright. I have not used a Maxwell, but the GG/Fresnel combination in my Crown is the nicest such combination I have used, including those in my ARCA and Walker Titan.

[IanG]

My Crown Graphic has a screen from Steve Hopf, when I firts fitted it I was very disappointed it seemed dim, but I fitted a fresnel 6 months agp and the combination is superb.

In my case the fresnel is fitted to the rear of the screen (externally) so there's no focus plane issue, it's still slightly less efficient than my Wista combination screen.

Ian

[Glenn Thoreson]

If the camera is equipped with a fresnel screen you must use one of the same thickness, or shim the ground glass to the original position. If you don't pay careful attention to these issues it will throw the plane of focus off. There's no reason I can think of that would make the screen dim, other than dirt or heavy scratches. Well, that and an f/12.5 lens. Try cleaning your screen with warm, not hot, water with a little dish soap. Don't rub the fresnel with anything but your fingers. It scratches easily.

[IanMazursky]

The Crown graphic fresnels come up on ebay every now and then.
I found a brand new one a few years ago for under $20.
Mine was very scratched up from 50+ years of abuse. The new one really helps.