I took some nice pics today using my Canon 7D and 50mm F1.8 lens reversed on a set of extension tubes. For a comparison in magnification I also have a beetle that I took with the extension tubes and then with the 50mm F 1,8 lens and a set of magnification filters. I used Kenko close up filters with the No 1, No2 and No 3 filters stacked on top of each other. This allows you to focus much closer with full aperture, shutter and auto-focus control, but you can't focus as close as with the extension tubes.
I have a also included a photo of a match head on a canon lens carp to show the difference in magnification between the close up filters on a 50mm lens and a set of manual extension tubes and a 50mm F1,8 lens reversed on top, As you can see, the amount of magnification is dramatic, and this was not even a full set of extension tubes....
Using the extension tubes and reversed 50mm F1.8 lens
Using the 50mm F1,8 lens and set of Kenko close up filters.
Using the extension tubes and reversed 50mm F1,8 A lens.
Taken with the Canon 7D and 50mm F1,8 lens and a full set of Kenko Close up filters.
Taken with the Canon 7D, a set of manual extension tubes and a 50mm F1,8 A lens reversed on top of the tubes.