As far as I understand all three options help you do macro photography but are their other reasons for having the three different items? I figured reversal rings and extension tubes were just for the low cost but with additional more expensive features being added to the two options it seems there may be certain situations for each type? What are their biggest differences and advantages over each other?

• Are there situations where you would have one over the other?
• Do all three options have the same "wafer thin" depth of field?
• Do they all suffer from the same light loss?
• Do any of them affect your photos more negatively than the others?
• Can I achieve the same magnification with rings and tubes that I can with proper lenses?
• Would you ever combine these options together or would there be no need for that?

I ask because I recently bought a cheap extension tube and reversal ring and I'm trying to get a better overall understanding of each. I tend to use the extension tube a lot more, because I can put it on my 70-200 and have a workable distance between subject and lens.

This photo was taken with 49mm of extension tube on the 70-200 I believe which may be greater than 1:1. Would it be sharper with a macro lens?

Herd of Shells http://pcdn.500px.net/4262483/ef9cd6cec7910a059dd2610bf627823d1707453e/4.jpg Larger Version on 500px