I posted this in the landscape forum too...no one had an answer...hope someone here will. I found a good deal on a pn 11 extension tube..only $100 in mint condition and I would like to get into some macro work. I'll be using d80 and 50mm 1.4, and a 70-300zoom with it. What kind of magnification would i expect? I understand there is no metering with it or is there spot metering? Is it worth the investment? thanks!