So here is my Linhof groundglass. Unless I am a total idiot, there is no fresnel. So help me out:

1. What frensel sould I get? Something economical I hope.

2. Can I install in myself?

3. I think I am going to order a satin snow GG, can I put the fresnel onto it once the new GG arrives (which could be a while, or so I'm told)?

Thanks once again. I am really looking forward to having a brighter GG. I'll be a whole lot more excited about shooting LF once that happens.