Hello! I've just recently entered the DSLR world by purchasing a Canon 30D along with an EF 28-105 3.5-4.5 II USM lens.

Yesterday a friend was showing off his new Nikon P&S (not sure which model). We were at a table and wanted to see what our cameras could do for macro photography, so we grabbed a small mint from a candy jar and tested it out. I was amazed at how well his camera performed - he had his camera focusing right up against the object, and the mint filled the frame beautifully. My camera, on the other hand, performed terribly. The 28-105 has MACRO written on it, but advertises a close-focus distance of 0.5 meters... I focused at 0.5 meters and the mint was tiny in my frame.

How can they call this a macro lens, when it's close focus is so far away? I thought I had purchased a nice lens (well I still think it's nice) but that little P&S blew me out of the water. If this is how things work, why aren't ALL lenses called macro?

So that's my first question:

1) Why do they bother calling it macro in the first place?

My other questions are:

2) If I want to be serious about macro photography, should I purchase a *true* macro lens (something that can close focus better than my 28-105) or should I use extension tubes instead, or a combination of both?

3) What are the basic rules for extension tube length (assuming there are any), so that I can apply this to the use of my 28-105 lens?

4) For understanding/purchasing extension tubes or diopters, how do I interpret the numbers of the charts on this page (see link below) which detail extension tubes and diopters?

http://www.bobatkins.com/photography/eosfaq/closeup.htm

I know those are a lot of questions - even if you just post a reference to another site/article that I was too stupid to find, I would appreciate it! Thanks!