I hear it time and time again…”Why do I still see black bars on my new widescreen TV?”
Without getting too technical or asking you to dust off your middle school geometry textbooks, here’s the basic facts about Aspect Ratios:
Fact 1) There have been several image formats developed over the years.
Format A) The NTSC television format is an almost square image roughly 4 units wide by 3 units high. If you bought a “big screen TV” in the early 90’s it would look like the familiar shape you’re used to watching all those I Love Lucy re-runs in. It is an aspect ratio of roughly 1.33 to 1.
Format B) CinemaScope was developed for the movie theaters. It has a very wide 2.35:1 aspect ratio so a 40-foot wide screen was only 17 feet high. This helps us feel enveloped by the image and brings us into the movie. 
Format C) ATSC video, commonly known as “High-Def”, is 16 units wide by 9 units high. A little math will tell us that an 8 foot wide screen would be 4.5 feet tall. This is the format of all of our HD football games (GO COLTS! SUPER BOWL CHAMPS!), HD soap operas, HD sit-coms, made-for-TV HD documentaries, etc. It results in a 1.78 to 1 aspect ratio.
Fact 2) All these formats are currently being used.
When you channel-surf between Sponge Bob at Bikini Bottom on Comedy Central and Bikini Babes on HDNet, your TV automatically switches between the NTSC image at 4:3 ratio, and the 16:9 widescreen ATSC signal. (Sidebar: I rhetorically asked a friend why we needed wide screens to view all these slender models which take up only a small part of the total screen width. He answered: “so we see more of them at the same time!”.)
If you watch a box-office movie, it was shot in 2.35:1 CinemaScope format.Fact 3) TV’s don’t stretch.…yet.
Fact 4) Very few TVs suffer from the “burn-in” problems that were caused when some of the pixels (colored dots that make up the image) were used more that others. LCDs aren’t affected at all. Modern plasmas “Wibulate”, “Wobulate”, or do other engineering magic to virtually eliminate the problem. The Stretch Mode on your 2001 widescreen plasma was an attempt to solve this problem by stretching the 4:3 NTSC video image out to the edges of the 16:9 screen.
Because the burn-in problem is no longer a concern, I present to you Fact #5:
Fact #5) It is OK to have bars on the sides or top and bottom of your screen!
Our custom remotes even have aspect ratio buttons to let you quickly select the correct ratio and avoid “watermellonhead”.
I wonder if we’ll have this problem when 3-D TV becomes available? I can hear the couch conversations now…”Do you think Jay Leno looks too Deep?”
Howzeedooit?
My design team at DistinctAV publishes this monthly newsletter that is full of ideas that enhance your home and office. If you’re remodelling, building, or just interested in the practical application of home electronics and controls, subscribe to The Design Perspective.
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