Hi all, I just realised that the extension tubes won't work with the ist D, because they do not have the A contacts. Any lens connected through the extension tube will not work correctly on the istD, because it will look like an M or K lens to the body. Then I read the trick of using old M or K lenses on the istD by rotating the lens a little or eliminating the aperture coupler. This makes the lens "useless" on analog camera's. However, one could by a cheap short extension tube get rid of the coupler in it and use it with a lens. You will lose infinity focus though but your lens will be intact.
Frank