If you set a Nikon D7100 menu to enable release by the manufacturer's ML-L3 infra-red controller and set the menu item that lets you fire the camera without a card in it. You can demonstrate the operation from an amazing distance - far further than I would have credited it. Full marks to Nikon.
If you set a Nikon 7000 to do the same thing it won't. You must pore over the controls until you discover the firing control ring concentric on the left hand top of the camera - sure enough there is a little pictogram showing an IR remote. Then you rotate the ring to it. And then set the menu item to give instant IR release. Then check you have a card in the camera - IT WON"T FIRE WITHOUT A CARD. As I discovered trying to demonstrate this morning...
I can only hope that they will be this diligent when the next model of this fine camera comes out.
Quiet word to the Nikon designers: Spare a thought for the studio workers who want to fire a flash system but do not need to change their shutter speeds - and certainly never want to climb above the highest synch speed of 1?200 or 1?250 of a second. Do like you used to do on the D3 - give us a positive lock button or setting for the shutter speed so that we can't inadvertently change it with the heel of our hand...Please.