im wanting to do macro with my manual focus four thirds OM lenses. i have seen those micro 4/3 extension tubes - macro extension tube 4 Panasonic G1 G2 GH1 GF1 micro 43 on eBay (end time 08-Jun-10 07:48:36 BST) and If i went for the micro 4/3 tubes i could use them with my micro4/3 lenses AND my four third lenses like so - but im concerned that the smaller diameter of the micro 4/3 tubes would mean less light gets to the sensor (making it harder to shoot), the tube diameter of the OM extension tube is much larger. would this be a fair assumption? or would you say the difference would be minuscule? which would you say would be best? Has anyone tried the m43 extension tubes?? if so are they good quality? Thanks.