Angles Of View
The phrase "Home Theater" brings to mind a series of images which are, well, nearly as diverse as what is seen within them. There are private houses today which contain exactly that, an actual movie theater with auditorium seating, a projection booth, and, doubtless, a working popcorn machine and soda fountain in its lobby. At the other end of the spectrum is what we might call a souped-up televison set that has some auxiliary sound speakers attached to it. And everything in between. Across this gamut runs a range of products and designs which get combined to create, at minimum, a viewing experience which is somehow enhanced beyond what we normally think of as old- fashioned "watching televison." How all this came to pass is interesting and this article will look at a few of the most important elements which have gone into the development of
Home Theater - Setting the Stage"Home Theater" as a phrase and as an industry is dedicated to the presentation of moving, kinetic images. The "purpose" of those images is principally to entertain; it is not generally to inform. The distinction between those two verbs is important and many of the design parameters which enhance one detract from the other.
To illustrate what we mean by this, let us imagine that we enter, some weekday morning, the corporate boardroom of a valued customer. We will seat ourselves in upright chairs along or around a large conference table and our attention will be directed towards a screen either handsomely encased before, or neatly installed within one of the walls before us.
Typically, the "show" will be controlled by a fellow member of our audience and the way that we'll know that it has begun is because he himself will provide the "soundtrack" intended to accompany the series of images before us. These images will change at intervals no faster than once a minute and often much more slowly. Even though the images have been designed to be as individually recognizable as possible, and even though their technical values may well be high, to understand them fully their audience is still likely to require an accompanying narrative from the person speaking their soundtrack.
Of course, while we're experiencing this show the room lights have been left on to help us not only see the soundtrack producer but also the other members of the audience and the yellow pad before us onto which we are expected diligently to scribble notes. Those notes, by the way, will not contain (except surreptitiously) our opinion or review of the show. They will instead more typically contain its summary. Lastly, while the list of objectives for such a show will often be long, only rarely will our entertainment or enjoyment be at its head.
Long before any of us ever saw a show of the kind just described, all of us have been familiar with two other kinds of shows: the movies and television. Historically, even though the creation of the former much preceded the development of the latter, in the experience of most of the readers of this article, the exact reverse is more probably the case. Anybody who is under fifty has certainly spent many, many more hours before a television set than she has ever sat in the movies. Paradoxically, then, even though the phrase Home Theater connotes the reproduction of cinema-like entertainment within the home, its actual historical roots are much more tightly entwined around blueish CRT tubes than silver screens.
Part of the decision to format Television as a 3:4 medium was done to avoid the necessity of cropping the vast reservoir of Hollywood films from which the fledgling industry expected to draw for desperately needed programming filler. However, the derivation of the NTSC broadcast standard (and its aspect ratio) emerged from other, non-cinematic limitations as well.
Looking back from the perspective of the 21st century, it may be hard to remember what an astonishing development Television in fact was. A clunky box could be plugged in in our living rooms and, at the mere twist of a dial, not only miniaturized movies, but images of real, live talking people were there before our very eyes every single evening we wanted to watch them. It was, truly, a watershed development which, it might be argued, has by itself irreversibly and profoundly changed our culture.
Quite mistakenly terrified by the sweeping popularity of this upstart medium, Hollywood reacted by making lots of movies in aspect ratios which, it hoped, would compellingly attract mass audiences back into its theaters. Screens and budgets became huge and images became wide (often very wide) and any number of efforts were made to reveal what film could do that TV could not. (It is interesting to speculate whether the genesis of the film industry's high-tech special effects emphasis might not be found in this original and frantic effort to distinguish itself from TV.)
With respect to Home Theater, this historical separation between film and TV can now be seen ironically to have vanished. Television is about to become wide-screen and the movies are about to become electronic. Both are interested in the big picture and both are big business. So, by now, is Home Theater.
In the pro A/V world, the development of big pictures, projected on big screens, was a function of the size of the audience. Commercial organizations weren't interested in spending money on presentation systems suitable for only two or three viewers. Quite to the contrary, their conference rooms had to be designed to serve groups much larger than those. In Home Theater, however, the virtue of a Big Picture was exactly that, a big picture.
Throughout the 1980's television manufacturers struggled to establish wide market acceptance of the first "big screen" projection television (PTV) sets. It was in service to this product line that the first Fresnel/Lenticular rear projection screens were developed. Because the 3-gun CRT projectors utilized by those early sets were anything but powerful, the inclusion of some sort of high gain screen system was mandatary if the consumer was to be tempted by the picture quality. Yes, at 67 inches in diagonal, it was certainly bigger than his TV, but it had also to be at least roughly as bright as well.
Another benefit which screen manufacturers brought to these early PTVs was a molded matrix of black stripes which when placed as a third element in front of the lenticulated and Fresnel layers, did an admirable job of increasing the set's perceived contrast even under relatively high ambient light conditions. Because the resolution of the broadcast source material (NTSC or PAL) was relatively low and because the direction of both the stripes and the lenticulations beneath them was perpendicular to the raster, moiré fringing and other interference patterns often created by black matrix screens could initially largely be ignored.
Early front projection alternatives in homes that wanted a picture bigger than what could be seen on a self-contained direct view set, tended to rely on curved screens because, once again, the projectors back then were extremely dim but, at least with a parabolic screen, if you sat directly in front of it, you could watch a reasonably bright picture.
By the middle 1990's, however, the Home Theater industry had begun to acquire a much broader currency which in no small part was due to two men who spent quite a lot of time and energy telling everybody in it how bad it was. These, of course, are Joel Silver of the Imaging Science Foundation www.imagingscience.com/ and Joe Kane of Joe Kane Productions www.videoessentials.com/.
Together they set out to teach anybody and everybody interested in enjoying a good picture from their home entertainment systems (whether direct view or projected) just what a good picture was and how to create it. That often meant that the manufacturers' factory settings on much of the hardware had to be completely discarded in favor of a quite radically different group of settings which, when accomplished faithfully, greatly improved the quality of the resultant picture and of its sound.
Since so much of the programming which gets watched in Home Theater has a quite specific and very well defined set of production values, those values should, assert Silver and Kane, be respected and thus reproduced as closely as possible in their viewers' living rooms. Thus, if the director of a film we are watching has been careful to costume his heroine in a gown that is robin's egg blue, it is, aesthetically at least, regrettable if we see it on our screen as being some other color, like, for instance, purple.
In some sense, inaccurate colors in entertainment media deserve to be thought of as artifacts-attributes or qualities of the presentation which by their presence distract attention from the presentation itself. If as a result of having a big screen, we see widely spaced raster lines threading across our picture, we are not going to be content. Similarly, if the grayscale or contrast ratio of that same picture are not properly set and calibrated, we should be equally dissatisfied. How exactly to avoid these and other picture imperfections are what Silver and Kane have so admirably taught. How to select and install the optimal projection screen is now what we have to learn.