The fact that a source outputs at 1080p in no way reduces the need for ISF Calibration.
But does reduce if not remove the need to have it per port. And it was more the HDMI part of my statement that was important.
The digital levels output by modern devices are spot on from model to model, make to make. Black is black, and white is white, and all the in betweens fall into place. So ISF calibration can be applied at the output by an external device.
Though if you do still have analog devices, there will be issues with that, because they all vary slightly from one another. And per device tuning is needed. The simple solution to that, is don't use analog devices.
