I think the short way to say this is viewing angle. If you're seated where the angle between one edge and the opposite edge is more than a typical situation, th

I think the short way to say this is viewing angle. If you're seated where the angle between one edge and the opposite edge is more than a typical situation, then you'll want more than typical DPI and thus resolution. One rule if thumb I recall hearing is that the TV diagonal size should be about 1/3 to 1/2 the viewing distance. I'd need to brush up on my trig to get degrees from that.