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I've got a new 1DX Mark ii with a new EF 100-400 telephoto and am shooting in  manual mode. I set the ISO to 1000 (not auto) for example and as I zoom in/out I'm finding that the ISO changes. Is this expected behavior? How can I turn this off so that...
I've read through a numbrer of other posts here for different camera with seemingly no solution. This "appears" to be a software, not a mechanical issue as the unit will zoom out while resting, nobody at the controls. I didn't see anything address it...
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