Just returned from two weeks spent in Africa: Uganda to view the gorillas for two days and Serengetti and the crater for four more, an additional day in the parks outside the crater also.
I brought the 18-55 but used the 100-400 85% of the time and marveled at the OIS function. Used bean bag on the Land Cruiser, when needed more throw. This lens is special and with proper use of ISO can be used in low light situations nicely. Made big mistake of being on Manual focus ( unrealized) for a day and missed half the shots until I corrected.
Used the big battery grip which I think is essential for long days shooting and multiple shots on CH. Bring plenty of batteries (7) and recharge at night. I brought a battery power pack in case I was away from electricity for a night. Shot JPEG and RAW in #1,#2.
Highlight was a treed leopard that posed nicely for twenty minutes, but saw all the animals as the weather in January was superb. Hope this helps.
Paul
