If this is a major trip for you (meaning, you don't go to Africa all the time), I would not trust the Bigma under safari conditions. I owned that lens for a couple years and it worked flawlessly under good lighting at local soccer games, etc... I took it on 3 major trips and it locked up and had major problems on each trip. Never again! lensrentals.com review says it has a higher failure rate than most other lenses. If it were me, I would not want to be on a once or twice in a lifetime trip and not be able to take any pictures. Consider the $500 to rent a 400 2.8L IS as just a small part of your $10,000+ trip and a chance to use a really cool lens .