While it's true that tubes maintains a lenses quality, they also restrict the ability to focus to infinity, as do lens diopters (the focus range stops way short of infinity). Add to that that in order to change the magnification ratio you need to add/remove tubes/close up diopters (filter lenses) & even then you are still restricted. The true macro lens has the least restrictions on its use (variable magnification ratio , no need to add/remove anything & retains infinity focus), but is also the most expensive option...
stevebein wrote:
Consider otehr options.
Pro's have used the Nikon and Canon ( or others) quality close up lenses, also, adding extension tubes maintains the quality, but cuts down the light. A lot cheaper than a new lens, lighter and with the filter options, significantly less volume. All work very well, I have used all options and they work very well.