Sinar Norma 5x7 Fresnel lens

[GeorgesGiralt]

Hi !
I own a 4x5 Norma and recently got the 5x7 conversion back.
My 4x5 back has a Fresnel lens which is inserted into a frame. This frame clips onto the back, on special ground glass retaining clips.
I've seen Sinar 5x7 Fresnel lenses, and they all seem to come without any dressing ;-) Naked as their first day.
Is this normal, and if yes how one mount them onto the back ? I better know before shopping as the price tag is somewhat , well, high ?
Thanks a lot for your help and advice !

[Struan Gray]

I have an original Norma 5x7 Fresnel and it goes on the lens side of the glass. To fit it, you remove the ground glass, place the Fresnel into the well and replace the ground glass on top of it. There are thin tabs on the short sides of the Fresnel which hold it in, and which act as spacers to move the ground glass backwards the right amount to correct for the focus shift introduced by the Fresnel.

I don't know if the more modern Fresnels are the same, but that's the Norma way. I *think* the process is described in the Norma manual that is online at www.cameraeccentric.com.