720p vs 1080i

I think that format is converted many times between stations but bandwidth (usable information) stays the same. 720p should be better on the standard TV since human eye is very sensitive to horizontal misalignment that comes from interlacing but in digital TV everything is converted to individually addressed pixels anyway. I have 42" DLP TV and switched mode from 1080i to 720p many times - could not see absolutely any difference. I don't know why many stations transmit in 1080i since, according to my friend who knows more about image processing, 720p is easier to compress.

I have a friend who is a certified ISF technician and has calibrated 1000's of televisions. I stand by his advise. At 50" or less there is no difference to the human eye between 720 and 1080. Larger than that and the difference MAY be apparent, or not depending on your distance from the screen.

I believe you meant to say that at 50" or MORE there is little difference and that differences may be apparent at LESS than that distance. While I'm not sure that 50" is the threshold, the differences in higher resolution picture quality, i.e. 1080p v. 1080i or 720p, are much more discernable at closer viewing distances.

Thank you for the clarification. I meant to say that at 50" diagonal measurement displays or smaller, the differences between 720 and 1080 are insignificant. I did not mean at viewing distance. And, although most displays are good out of the box, all displays can be improved with calibration. The spec sheets and reviews show some displays come with virtually perfect calibration already and others benefit greatly. It varies from model to model. There is the room in which you are watching, and the source may determine the quality. Some displays have individual settings (some user accessible and others only technician accessible)for each source. There can be a great difference between the calibration for DVD-SD vs Blu-Ray vs over-the-air HDTV. I am not an expert, but this is what I understand to be true.