Does anybody know if Canon's life size converter is compatible with the Zeiss 50 or 100mm macro lenses? I am curious how it would compare with extension tubes, if I wanted to get to 1:1. I have used the life size converter with canon's 50mm and 100mm macro lenses where it gives 1:1 and 2:1 magnification respectively. I generally find the life size converter gives better results than just using extension tubes to get the same magnification. So I am curious if anybody has used it on third party macro lenses?