I am trying to understand the issue brought up by Moose Peterson on using the F5 with AF extension tubes. The claim is that the RGB metering does not work when using any extension tubes, including the Kenko ones with AF electrical contacts. I haven't heard any specifics on exactly what happens with the AF tubes. Having the Kenko AF tubes, I tried this out and could not see what the problem was. The camera still remained in RGB metering mode and seemed to be metering fine. I know that the F5 has one extra contact point (8 total), but the lens I was testing (105mm AF Micro) only had 5 to begin with. The Kenko tubes have 7 contacts - so it seems to cover all the contacts of the lens. So why would a 5 contact lens work with RGB metering and not through the 7-contact extension tube? If anyone has some experience with using the AF tubes - I would appreciate your comments. This is a bit confusing... Mark
