All very good points. I'm in the same position, will be on Safari in Kenya/Tanzania for 8 days and havent figured out yet what to bring.
At the moment I'm strongly considering bringing my 5D3 as my (only) DSLR and:
- Buy the Tamron 150-600 as main lens for the whole trip
- Bring the 24-70 II for the landscapes and environmental shots (but considering the dust, that would stick on the 5D the whole day, hmmm)
- Get a RAW capable point & shoot (e.g. the G1X II?) in case wildlife gets very close and for the shots in the villages, environmental shots, etc.
Would like to prevent bringing a second DSLR body as we are already hassling with the weight limit of 15kg.
Although an other option would be renting a crop body and use my 70-300L and keep the 24-70II on the 5D3 but wouldn't that spoil the quality of the more distant wildlife?
Would love to hear your thoughs on that.
You seem to be on the right track. Unless you are into bird photography, 600mm is mostly good enough on full frame.
Crop frame would give you perfect IQ till about 400 ISO. I would recommend the full frame option.
When you will change lenses from tele to that wide it would mostly be in your hotel room or a not so dusty environment. Wildlife and tribes will be far apart and give you enough dust free options to change lenses.