I used to love playing around with extension tubes and teleconverters on my film camera days, back when I was was a wee lad and could only afford 1 lens and 2-3 rolls a month. So FINALLY- I got extension tubes that aren't "dumb," I've always been put off by focus by wire lenses in general, and not having electrical contacts to control aperture and focus etc. So these have me stoked, and I got them a little less than the going rate (even better!). I did find that I didn't have the problems that other people had- I could stack them on most any lens and still get it to work, stacked on the Panasonic 14mm, 20mm worked with no problems. It runs into the problem of close focusing of course- the stacked 10mm+16mm with the 14mm lens gave me an impossibly close focusing distance from the front element that would make it useless in any practical use. Although I'm a "photo-enthusiast" I also am a fine artist (fartist), and do some photography in my art work at times and almost exclusively with film + virtually all macro- and by no means do I consider myself a "pro." So being able to combine my art work equipment with my enthusiast hobby equipment is A++. Olympus 12-50mm w/10mm&16mm stacked (a little shy-ish of 1:1 macro): Olympus 12-50mm w/o tubes in "macro mode": and just for size reference: Crazy Panasonic 14mm w/ 10mm&16mm tubes stacked: What the Panasonic 14mm was pointed at: Heh- I was also kind of tickled that they included the equations for figuring out the magnification, for some reason I wasn't expecting that- I was just expecting tubes in a box. I guess that's just my experiences from buying "dumb" tubes + adapters on e-bay : The tubes should help streamline my own art, and should make for some fun on hikes (I'm they guy who likes to take photos of slime mold on hikes).