Q: can i connect my canon 7d to my iPad air

Canon has an App for their camera models that support WiFi. If you have one of these models check out that App in the App Store.

You can with a cable for picture download but I don`t think for remote use. I got a Sony and can only download pictures

Using the Apple iPad Camera Connection Kit with iPad - Apple Support

You can connect your Canon 7D to your iPad Air to download photos from the camera to the iPad. You need two items to do this.

1. You need the USB cable that came with your camera. it has the small USB connector at one end and a standard USB connector at the other end.

2. You need a Lightning to USB Camera Adapter.

http://store.apple.com/us/product/MD821ZM/A/lightning-to-usb-camera-adapter?fnod e=3a

There may be some way to do remote shooting but I'm not sure of this. I suggest you ask the question on a forum specific to cameras like Digital Photo Review (DPR). http://www.dpreview.com/forums/1032