Hi

I just baugt a (pacemaker?) Crown Graphic with a 135 Optar lens.

The ground glass has a frensel lens on it. I am noy used to seeing this on a 4x5 camera.
Is it normal?
Why is it there?
Can I remove it without effecting focus?
Is focus ok and normal with it in place.

It is positioned so the frosted side of the glass is against the rough side of the frensel With the frense closer to the lens Is this correct?

Any other answears to questions I should of asked would be appreciated.

Thank You
Pat L