I went yesterday to try it and I tried to use all metal but the detector is really sensitive and it was sounding everywhere, so I decided to put disc. at 40 as Monte said in one of his posts and I started recovering nice targets. I 'm still in the learning process and I don't even now in which tone I was working but Iron was sounding as a bass tone, pull tabs a mid tone, and high conductivity coins a high tone. Anyways I ended up tripling my recent coin finds. The last two recent hunts I was using my compadre and found 2 watches,and 5 coins plus 2 celulars. Yesterday with the O8 I found 11 coins some really old Mexican coins, 2 watches and 7 celulars. The difference, I guess, with other detectors I have used is that the O8 seems not to be masked at all by iron. Another thing I like is that it sounds like crazy when there is something big in the surface or within 2 inches of soil, for example a crushed alluminum can or a big piece of alluminum foil. I also got surprised at the end of my outing, it was now dark and I was swinging the detector in the way back to my house when I got a big signal in the middle of the road. It was a quarter reading of 82. and I scanned the signal for size and it was small, so for me it was a coin, but I know that it could be also a big crushed alluminum can way down there. So I made a big hole aprox with my pick of 6 x 6 inches and the sound was still there, so now I thought I had a can really deep, and I was going to quit. But I decided to dig it since I'm in the learning process, so I dropped close to 4 hard drops of my pick and removed the dirt from the hole. I did not have a flash light but I had the centech pinpointer which has a light, I started looking for the big can in the dirt and there was nothing, nor in the hole either. So now I started looking fot the qtr more closely with the pinpointer. And there it was, not a qtr but a memorial cent all with green patina dated 1967 and I know it was at least 7 inches deep and it sounded hard, even to make me believe it was an alluminum can. Thanks a lot for your help to all of us Monte and to all others that also help the new members. The O8 is now my main machine.