Perhaps someone can help... I purchased the Fotodiox extension tubes for my G3 a few months ago - I could not get them to work. I can't get them to focus on anything... I really thought that it was operator error (probably is...) but I took them to my photo class last night and even the experienced instructor could not get them to work. I assumed that I needed to turn on "shoot without lens" so did that but beyond that I don't know what to do. Any suggestions?