Originally Posted by LoneSierra
The 400 fixed is lighter than the two zooms under discussion. Here are the weights of each lens in pounds:
1.7: 200mm f/2.8
2.3: 200mm f/2.8 with 2X TC
2.8: 400mm f/5.6
3.0: 100-400 f/4.5-5.6 IS
3.2: 70-200 f/2.8 IS
3.8: 70-200 f/2.8 IS with 2X TC
I don't want to be a broken record, but the 400mm f/5.6 is really a great deal if you want the absolute highest quality: it can match the $6,000 super telephotos, which are in a totally different class than the $1,500 zooms, despite the fact that it's cheaper.