So I got these tubes the other day, and I said I would test them, particularly with the 45mm f/1.8 to see how it performs as a macro lens. So I went into my garden and said, hey, looks there's a flower, that'll do. I took each photo at the closest focus distance possible, to give you an idea of the increased magnification possible. Click for full-size JPEGs. The 45mm on its own: With the 10mm tube: With the 10mm and 16mm, 26mm extension in total: Here's a pic taken with the 10mm + 20mm f/1.8 of my finger: And here's a pic of the tubes, I've decided to store them in my bag between my spare body and lens caps, to avoid dust getting in. They are made entirely of plastic. They wobble a bit. I can confirm that AF works just fine with the tubes, however it's next to useless because the permissible focus range is not that large. Best to just set it to the minimum, and focus by moving the camera back and forth. These shots clearly weren't taken under any sort of test conditions, so shouldn't be taken as any sort of indication of the quality possible. If the lens you're using has sharpness to spare, it will be fine.