i've read foreign photography forums and find that its common practice for people in the US/UK to "return" lens (which they find to be soft) to the shops/on-line retailers for an exchange. is this policy applicable in Singapore photo shops? am asking not so much to determine if this is allowed, but more to find out if such returned duds find their way back to the shop to be resold to an unsuspecting customer. i don't even know if Canon/Nikon Singapore even accept lens returns or recaliberations. anyone knows? thanks.