
Originally Posted by
Ed Vatza
I know you asked for advice and I'm going to suggest a book. I just finished reading "Understanding Close-Up Photography" by Bryan Peterson (the guy who wrote the classic "Understanding Exposure"). It just may be the best macro/close-up book I've read and I have about a dozen of them. In it he goes through all the options: macro lenses; tubes; close-up lenses/filters like the Canon 500D which you can add to your 70-200; he even talks about shooting wide angle close-ups (with a 12-24mm lens and a 500D) and other interesting combinations. The book is about $17 on Amazon and may be the best $17 you'll spend.
For what it's worth, I use the Sigma 150mm and 70mm macro lenses. I also have the Canon 500D close-up filter and I have a set of Kenko tubes. I use them all for different purposes. If I had to choose just one, it would be the lens and I would go with something longer than the 100mm like the 150mm or even an 180mm (You can go with a Canon; Nikon has a 200mm, I believe; Sigma; Tamron; they're all good). You really will want a lens with a tripod mounting collar. It makes it a whole lot easier to go from landscape to portrait and back again.
Hope this helps.