p.2 #2 · Close-up capabilities of 100-400 and 300 F/4
I found that using extension on a 100-400 did not work as well for me as Canon's 500D diopter. I agree with others that a dedicated macro can be better. However, the diopter is lighter than a 100mm macro and way lighter than a 180mm macro. So, if I am hiking, I can take it along and the 100-400 doubles as a tele and a macro lens with the diopter added on. That said, with Pixelperfect's images, I will have to try the extension tubes again!
p.2 #3 · Close-up capabilities of 100-400 and 300 F/4
I just picked up a 400 f5.6. I also have the 100-400 and the 300 f4 IS. I wanted something lighter then the 100-400 when I was going to be at the 400 most of the time. I found the 100-400 is a great lense when you want versatility, but if you were going to be at 400 all day the 400 f5.6 is a better choice.
If I were using it just for close-ups the 300 f4IS is the way to go. I feel it has better IQ then the 100-400.
p.2 #4 · Close-up capabilities of 100-400 and 300 F/4
There are quite a few flower shots taken with the 100-400L in this gallery - in the middle to the end. Most are handheld. http://www.pbase.com/bander/back_yard_06
