>>3376743Sure, you theoretically need additional batteries if you want the same performance since the Cipa rating for the a7rIII is 650 shots and for the D850 its 1840 shots.
Normal photographers who dont shoot weddings, events, sports or such things dont burst trough hundreds of photos in a few hours (in which case the battery lasts longer than the cipa rating) though, so one battery easily lasts for a whole day of shooting.
One NP-FZ100 battery weights 83gr, with two additional batteries this means an additional weight of 166gr, not 500, and shouldnt be of any problem to carry even in your pockets. An iPhone Xs is heavier with 177gr.
In the calculation above the battery weights were included. In the end the only weight that truely matters is the weight you hold in your hands.
