Originally Posted by pjpjpjpj
I suspect that the original hookup was doing "anamorphic" stretch where it gradually stretches the picture more and more, the farther from the center of the screen you get. That typically hides the stretch much better. Then when things got switched, and you manually did the stretch, it was just standard "equal" stretch, where the entire picture was stretched equally, which looks noticeably more stretched.
But, as above, the SD content was surely being stretched.
Anamorphic actually refers to the process of squishing widescreen content horizontally to fit in a 4:3 format (people are tall and skinny), and then the display device stretches it horizontally back to widescreen, where it displays properly.
But, your point is taken. That sort of non-linear stretching you are describing makes things in the middle of the picture appear closer to correct proportions, but then things on the side are way out of proportion. When the camera pans in say basketball or football games, it looks like a wave. Yuck!