Canon Lens for African Safari
I currently own a Canon 7D and a Canon 5D Mark III which I plan to take on a trip to South Africa. I currently own several lenses which I plan to take with me, but I am concern reading some articles on African Safari that my lenses might not be long enough.
I plan to take a Canon 24- 105 f/4L IS USM as my general all purpose lens for the trip which I plan to use with the 5D mark III.
I will also take my Canon 70 -200 f2.8L IS II USM and the Canon Extender 1.4x III and Canon Extender 2x III which I could use with the 7D. Since the 7D has a crop sensor of 1.6, it will help with my reach issue. The 7D with the 70-200 and the 1.4XIII is equivalent to a 156.8 - 448 (f/3.92 ) and with the 2XIII its equivalent to 224- 640 (f/5.6) ( if my my math is correct). However, that might not be long enough for certain Safari.
I do not want to take a 400 or a 500 Canon Lens. They are very large, heavy and extremely expensive. I have enough with the gear I have to add such a large, heavy, expensive lens.
I have been debating if I should rent and or buy a Canon 100 - 400 f/4.5-5.6 IS USM to take on the trip in addition to the 70-200 f2.8L IS II USM I have and the two extenders ( 1.4X and 2X). This would enhance my reach equivalent up to 320- 1280 with the 7D with the crop sensor and the 2X. However, I am concern that the 2X III extender would degrade the quality and sharpness to a point that it might not be a good idea. The lens would be effectively an f/9-11.2. I am concern how sharp the pictures would be. I could use the Canon 100- 400 with the 1.4X III instead to reduce it down to a f/6.3- 7.84 equivalent, but the reach would be reduced on the 7D to an equivalent of 224-896.
Any experience with the Canon 100- 400 f/4.5-5.6 IS USM and the Canon 2X III and Canon 1.4III with the 7D?