i have recently bought a 7d and only have the 18-135 that came with the body. i know this question has been done to death but i have only always found a 100 - 400mm compared to either 70-200+1.4/2x or 300 4L+1.4. but im an avid (albeit amateur) wildlife photographer. what would be a better addition to my lens collection in the long run (i intend to upgrade to a full frame at some point much later) especially considering most of the wildlife/safari photography is done in low light conditions (at dawn/ dusk)
(70-200 and 300 f/4 and 1.4x/ 2x)
(100-400mm and 1.4x/2x)
i understand the budgets for these two set ups would be a little different but that's not a constraint unless it makes more sense to buy the 100 - 400 for now and save the rest for a 400 2.8 or 500 4 prime.