Yup, the camera is tethered to the computer for FoCal. It's fully automated for Canon as far as I can tell; for my Nikon I have to manually set the AFMA for each shot and tell the software to take the photo... much more inconvenient.Same here for the 5D3. You have to be careful not to displace the camera.
In order to use the FoCal software, the camera HAS to be tethered to a computer? Then how are people like Neuro calibrating a 600mm lens at lengths up to 98 feet? Is this a USB cable? Please advise, thank you.The target is at 98'. One does not need to be near the target. Just near the camera and the computer. And yes, it is tethered by the USB cable that comes with it - at least that is the case with my 5D3. Dont know about Nikon but I cant believe it will be any different.