So the time has come. Projectors have gotten cheap enough and good enough to take the leap. You've finally decided to dive into the world of large screen home theater. And I don't mean large screen as in a 50" plasma TV. I mean really big--a 100", or 120", of 150" diagonal screen with a great video projector. You want the excitement of the commercial movie theater at your fingertips in your own home.
Now, what's the first and most important decision you have to make? Most people immediately think "which projector should I buy?" But there is something MUCH more important than the selection of the projector. It is this: what size screen will you install, and how far will you sit from it?
Hard to believe, I know. But the truth is, to maximize the enjoyment of your theater, your decisions regarding screen size and viewing distance are all-important. All other considerations related to audio/video hardware are secondary. If you don't get the screen size right and place the seats in their ideal location, it doesn't matter what equipment you buy--you will never enjoy your theater as much as you could have.
Two Extremes to Avoid
There is not nearly as much attention placed on the vital subject of screen size as it warrants, so we will focus on it here. There are two huge mistakes you can make in selecting a screen size: you can make it too small, or you can make it too big. Both of these are monumental errors in home theater design. If you make the screen too small, you won't get the immersive movie theater experience you are hoping for. If you make it too big, you will get eyestrain and viewer fatigue that will make you not want to watch it as much as you might otherwise. Believe me, the last thing you want to feel is physically exhausted after watching a two-hour movie, and that's exactly how you will feel if the screen is too big.
Well then, how do you determine how big your home theater screen should be? Simple. You go to the movie theater and experiment with different seating positions relative to the screen. I went to a movie theater last weekend to see Bottle Shock, the new movie that is touted as this year's Sideways. It was nowhere near as funny as Sideways. In fact, it was a mere shadow of Sideways. It will never achieve the cult film status of Sideways, and I am personally outraged that they would dare to draw the comparison. But I digress.
The point is, when I entered the theater I spent some time to evaluate my seating options. Since the movie was Bottle Shock the theater was virtually empty, so the theater was my oyster. I ended up selecting a row that for me was the most comfortable viewing distance from the screen. After the movie, I paced it off, and found that the screen was 40 feet wide, and the row I had selected was 60 feet from the screen. Do the math and you will find that, for me, the perfect viewing distance was 1.5x the screen width. And believe it or not, that ideal ratio of screen width to viewing distance holds true whether I'm in a movie theater or my own home theater.
So, if you are trying to determine your ideal screen size, your first assignment is to go see some movies in a commercial movie theater and pay close attention to the rows you choose. Do you sit in the front rows? Do you sit in the middle of the theater, or toward the back? This will vary by theater, based on the size of the screen relative to the depth of the theater. So you need to make some rough measurements by pacing it off. But the simple fact is this: the closer you sit to the screen, the harder your eyes have to work to see the movie. The wider the angle, the more extreme the eye movement required to see everything. You won't notice this in a few minutes of viewing, but after an hour or two, prolonged aggressive eye movement translates directly into eyestrain and physical fatigue.
Let's assume you are like most people. That means that since you are going to the trouble of installing a home theater, you are tempted to put in the largest screen your room can handle. Let's say that proposed screen is 12 feet wide, and you plan to put seats at a distance of 12 feet, which by my ciphering is 1.0x the screen width. Is that a good solution for you? Well, do the theater test. Go to a movie and pace off the width of the screen in the theater. If it is 15 paces wide, then walk off 15 paces from the screen into the theater and sit in a row that is 1.0x the screen width. Sit through the movie at that distance, and evaluate your physical condition after the fact. Are you eyes watering? Do you feel fatigued? Or were there no nasty side effects? Was viewing a movie from this distance a pleasant and comfortable physical experience?
If you feel negative effects from watching a film at a distance of 1.0x the screen width, take a break, then watch another movie sitting farther back. If the screen was 15 paces wide, try sitting at a distance of 20 paces from the screen, which is a distance of 1.33x the screen width. Experiment with this numerous times before deciding on an average viewing distance that is most comfortable for you.
As a side note, the type of movies you watch will have some influence on the results. After all, it is all about eye movement, which equates to eyestrain and fatigue. The more often, the more quickly, and the farther you need to move your eyes from right to left determines the amount of stress they are under. If you watch movies that are slow and lyrical in their visual presentation like Swimming Pool or Shine, your eyes will not move nearly as much as they will when watching 2 Fast 2 Furious, Casino Royale, or other rapid action films in the same genre. So when you do your theater tests, make it a point to choose movies that are, as far as the degree of action is concerned, similar to the type of material you will be watching most frequently in your home theater.