to ja zacytuję fragment:
" Canon's EOS 300D digital SLR comes with a lens in a new variation of Canon's EF format, EF-S. This has a projection on the rear, which prevents the use of old Canon extension tubes for close-up work. Canon have redesigned the tubes (new ones have a II designation - e.g. EF25 II), however if you already have one of the old EF tubes, this page describes how they can be modified to fit the EF-S lens, to save the expense of upgrading."

dalej opis przeróbki obiektywu do użycia z 300D