Going Widescreen: How Big is Big Enough?
Making the jump from regular TV to HDTV usually means switching from a square-ish screen to a flatter, more rectangular screen. Speaking technically, most of the TV screens we are used to have a 4 to 3 aspect ratio, meaning they are 3/4 as high as they are wide. Almost all HDTV sets have the “widescreen” format, with the slightly more movie-like 16 to 9 aspect ratio.
So, if you want to replace that old Trinitron with a similar-sized HDTV, you’ll need to do a little (very little) geometry to make sure your viewing experience will actually be better.
TV sets are measured diagonally, from corner to corner. So, because of its flatter shape, a 25 inch widescreen HDTV will be wider than a 25 inch regular TV, but will be lower in height. To match the height of a 25 inch regular TV (which is 15 inches, incidentally), a widescreen would need a diagonal measurement of 30.6 inches:
Maintaining the same picture height is important, because there’s still a lot of content out there that is designed for the old 4:3 format. This is what happens to regular content on a widescreen:
So, your new HDTV will need to be about 20 percent bigger, in the diagonal measurement, to display standard content as big as you are used to seeing it. If not, a good portion of the shows you watch will actually be smaller on the widescreen.
Of course, the easy option is just to “go big” with the new set. The extreme sharpness of HDTV, especially 1080p HDTV, makes it hard to go wrong by going too big.
