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Part 1: The Projection Aspect Ratio Dilemma

No simple solution to nagging presentation problem By Gary Kayye, CTS

I can't think of a more frustrating, seemingly unsolvable, display technology issue than what to do about the impending transition to 16:9.

If you read that and haven't a clue what I am speaking about, you either haven't had to make a DVD player work, seamlessly, in a projection environment or you have never had to design systems with the new-fangled laptops from companies like Apple and Dell that output 16:9 or 16:10 (what the heck were they thinking?) aspect ratios.

Here's the issue. If you take the (supposedly simple) application of connecting a DVD player to a projector or flat-panel display (or both -- and this is where the real doozey of a problem comes in) and try to make it work so that you don't have to manually change aspect ratios with different DVD material; you've got what I am speaking about. The problem is that you can't do it. And, now take that same installation and add one of those 16:10 Apple PowerBooks into the mix, oh boy!

First things first. Scenario with a 4:3 Display (projector or flat-panel monitor):

  1. 4:3 Display and a 4:3 DVD or PC: Simple enough. If your source material is always going to be 4:3 and you're displaying on a 4:3 projector or flat-panel monitor then there's really no issue to worry about. This has been the standard application of the ProAV market for 20 years or more.
  2. 4:3 Display and a 16:9 DVD: OK, a little more tricky, but still fairly simple. If you've got a 4:3 projector or flat-panel monitor and a DVD or PC that's ALWAYS outputting a 16:9 image, you can design the room, environment and the projected image around that. Of course you will have black-bands on the top and bottom of the displayed image as the source material is in a wide-screen format and your display is a standard 4:3 format, but it works. As long as the image height is tall enough, there's no aspect ratio switching needed or complicated programming to switch it. Ah, but when was the last time this application was exactly this way? Read on.
  3. 4:3 Display with a 16:9 DVD and a 4:3 PC: Now it gets tricky. The 4:3 PC is simple enough -- just project it (see #1). But, when you switch between that same 4:3 PC and a 16:9 DVD, this becomes problematic on a 4:3 screen. If you simply display the 16:9 material on a 4:3 screen, you have to deal with two issues: 1) the black bands/bars at the top and bottom of the screen and, 2) if the image height is tall enough for everyone in the room to see it. If you can overcome those pesky black bars, then you've won half of the battle. But, the other half is a bit more difficult to overcome. You can't just assume that the screen/image size picked for a 4:3 projected image is large enough for a 16:9 image -- in that same 4:3 space. You see, the problem is that the image height is not supposed to be shorter than what it was designed for. In other words, if your environment is designed properly, it was designed with the rule of thumb that the least favored viewers (those poor souls sitting in the back of the room) are to place their seats no more than six times the image height -- preferably five times. So, if you followed the rules and then you change image height (display 16:9 on a 4:3 screen) then you may throw off the location of the least favored viewers -- i.e. the least favored viewers may now be in the 3rd to last row and the two rows behind them are now comprehending nothing, visually. So, simply put, this is the wrong way to design an environment where you are switching between wide-screen (16:9) and full-screen (4:3) images unless you consider this in the beginning and no one is ever sitting beyond those rules-of-thumb locations regardless of image height.
  4. 4:3 Display with a Multi-Aspect Ratio DVD: This is not just tricky but tough. Let's assume you've designed your room properly for least-favored viewer seating regardless of whether you are displaying 4:3 or 16:9 material -- that challenge is out of the way. But, now you've connected a DVD player and you are playing an assortment of DVDs on your DVD player -- some 4:3 (or 1.33:1), some 16:9 (1.77:1), some even 1.85:1, and 2.1:1 and even 2.35:1. The wider the aspect ratio, the shorter the projected image on the screen. Now, as you move up in aspect ratio (think Star Wars Episode II, Armageddon and Titanic), the projected image gets skinnier and skinnier (horizontally) on the screen and at some point, the least favored viewer may be in the second row!

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    Related Keywords:display technology, projector, 16:9, 4:3, laptops, Apple, Dell, PowerBook, 16:10, aspect ratios, Gary Kayye, DVD, PC, flat-panel monitor

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  5. Part 1: The Projection Aspect Ratio Dilemma by DMN Editorial at Aug. 04, 2004 3:26 am gmt (Rec'd 3)

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