« on: May 19, 2013, 08:41:35 AM »
I have both the 70-200 f/4 IS and the 100-400 on a 7d. I shoot everything landscapes to portraits to birds. I can tell you that there have been several times when the 70-200 was not long enough for those distant landscape details, and that's on a crop, so on FF it will seem even shorter. That said the 70-200 is without a doubt the sharpest of the bunch. And it is sharp! The 100-400 is great for its versatility. I use it mainly for wildlife, but I have used it for outdoor sports as well. It is a sharp lens, but anytime I can switch to the 70-200 I do because it is sharper. The 70-200 is also considerably lighter and weather sealed. Weather sealing is actually something to consider with the 100-400, as it is less weather sealed than most lenses as the push pull design lends itself to the possibility of moisture on the barrel getting in the lens and damaging the tension ring. I do not have hands on experience with the 70-300L, but the 100% crops from it do look great. Not sure I can give you a definitive answer, but it sounds like for your needs the 70-200 or 70-300L would fit the bill.