Andreas,
Thats right, I also use the FX1e. To relay the full 36mm frame width, you need a zoom setting of 18mm on the zoom ring. You can actually go a little wider at about 37mm frame wide.
With zoom of 18 (almost the widest I can get without the edges of the GG to apear)
the frame is as wide as an EOS 10D frame with a 35mm lens (56mm field of view), taken side by side.
Andreas