Originally posted by Lowell Goudge While a bellows is the Best overall for macro, it is not an absolute necessity, and depending on th elens you use, will suffer all the same limitations as extension tubes.....
I second everything Lowell said; as usual he says true and wise things.
But I want to expand a little on the differences between tubes and bellows. The differences are not optical; they are equivalent optically. The essential difference is (perhaps minor) convenience.
Tubes require slow, disruptive operations of stacking/unstacking as you home in on the magnification and framing you want; with bellows, you turn one knob.
Typically almost 3 sets of tubes are required to get the same range of magnifications a bellows covers.
Finally, and not to be considered lightly, bellows are
WAY cooler looking than tubes! Impress both friends and strangers!