Thanks all.

I have a voigtlander, which is OK as David pointed out the meter doesnt work. My big problem is my Mamiya 6 where the meter works fine. I like Jeffs idea but the lens hood wouldnt let me see the edge of the cap. NOt keen about leaving the cap off as I dont like cleaning the front element much. Maybe I'll stick a note to myself on the top of the camera, might help.