7D shutter speed fall off

If your auto iso range is maxed out at a given shutter speed some Canon cameras have a Safety Shift feature which will overwrite the settings to ensure correct exposure. If that is sat to shutter speed, it will indeed lower the speed no matter the lower limit. Perhaps it’s the Safety Shift?
 
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Hi Ronald.
First did you mean ISO 16000 or 1600? I would think it must be nearly dark if you are up to 16000, not a big surprise it can’t sustain 1/1000s
It sounds like you might have the ISO range limits set to 400-16000 (or1600?), second red tab, it could still be that if you were expecting higher ISO’s!
It also sounds like you have safety shift enabled, it will ensure a balanced exposure if the settings are way off, not helpful in some circumstances.

Cheers, Graham.
 
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