Maybe you can see something if you don't intend to hit the ball back, but the reality is that you're not in the correct position to make such a technical judgement.
Originally Posted by yourmailman
On the idea that you cannot see a foot fault from 76 or 78 feet away ...
You can clearly see a flagrant foot fault from behind the baseline, no problem. I don't think you have to have great eyesight to do it, either. A flagrant FF is easily seen from that distance. In fact my camera was set up against the back fence, in the corner, some 90 feet away, and the FF was definitely visible.
I agree that you probably cannot see someone's toe touching the baseline, but when the majority, or all of their foot is inside the baseline before they strike the ball, you can absolutely see that from the other end of the court.