I was in South Africa this summer for Sardine Run. All carryon bags would be weighted if you have to fly in/out in Johannesburg. My friend was able to negotiate keeping her heavy camera bag but it took going up to the supervisor . The possible solution is to pack one camera body and maximum amount of lenses in your Cary on complying with Weight and bubble wrap the rest to the checked bag along with second camera body , this way you will have at least one set of gear should luggage gets lost or invaded.