I have cheap Chinese grips on both my cameras and have no issues with either. They look and feel much as the Canon grips would, and function exactly the same. Just as on my 15-85 lens, which didn't come with a lens hood despite its outrageous price (well into "L" territory) I bought a cheap Chinese hood at 1/10 of the price that looks and feels in all respects identical to the Canon one - only the writing is different.
Apparently it's different with Nikon. Instead of using the two batteries in parallel, they have a superficially marginally better system of draining one first before starting the other. I say "superficially" because it isn't problem-free, and probably won't work at all with a non-Nikon grip or battery.
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Watching the sun go down! booo
