A/V Veteran

It's been a while since I last opined on video projectors and screens, and since there are always newbies hanging about it seemed long overdue.

So you've finally decided that a video projector and screen will be in your (hopefully near) future. Flat screens are fine and all that, but they just don't give you the WOW! experience you're looking for. But how to proceed? If you think you can just go out tomorrow, choose a projector and screen at random, and have it all installed by Thursday, think again. To avoid costly mistakes you need to do some homework. Even if you choose a pro to do it (not cheap, but often a good idea), some of the choices involved will be personal.

Big TV vs. Projection
Before going on it's worth pointing out that BIG, flat screen 4K UltraHD TVs are getting cheaper. It's now possible to find a premier, 80+-inch 4K LCD/LED set, from a major manufacturer, for around $5,000 or even less. An 82-inch, Samsung Q90, as I write this, can be had for $5,298. The 85-inch Sony X950G is $4,000. That's still serious money for most of us, but two years ago you'd need a platinum card and a credit rating of 1,000 (is there such a thing?) to afford a top-class set of that size.

No similarly-priced projector we know of will come close to the peak brightness capability of these flat screen sets. This brightness offers the best high dynamic range (HDR) experience. Many projectors can "do" HDR, but they'll never be as eye-popping on those bright highlights as a quality flat screen set.

But keep in mind that the screen sizes above are diagonal. Even an 85-inch diagonal, 16:9 screen is only 74-inches wide. As projectors go that's small potatoes. Moreover, getting an 85-inch set into your home theater space isn't trivial. Don't even think about doing it without store delivery and setup, or a couple of strong friends with no back issues. While flat screen sets are getting lighter, an 85-incher is still a heavyweight. And you'll need a very wide and solid cabinet or table to put it on (and don't forget to secure it to the wall behind with safety straps), or a solidly built wall to hang it from (we strongly recommend professional help for the on-wall option). Moreover, the bigger the flat screen set, the more power it will draw. Your electric company will send you birthday cakes and Christmas cards.

If the jumbo flat screen set just isn't for you, a projector and screen are clearly your best big screen option. There are now two different types of projectors — conventional and short throw. A conventional projector is positioned at or near the back of the room with the screen up front, as in a movie theater. We'll stick with conventional projectors for now.

Projector Features that Count
Among the important features offered by most projectors are lens adjustments, and the most critical of those is zoom. For a given distance from the screen, the zoom feature can make the image smaller or larger. The available zoom range will differ from projector to projector; there's no standard. What you'll need to determine is the size screen you want, the maximum possible mounting distance of the projector from the screen, (the throw distance, more precisely the distance from the projector's lens to the screen) and whether or not the zoom range of the projector will fill your chosen screen at the desired projection distance. You can always plan to mount the projector further forward if needed, but its maximum rear positioning will depend on the depth of the room.

If you'll need to position the projector hard up against the back wall to make the numbers work, your chosen projector must have front and/or side ventilation ports, not rear ones. And if the projector's jacks are on the back (some are on the side) you'll also need to insure that there's enough space behind the projector for the cables. And don't plan on a sharp cable bend. If you need to use one of the new fiber optic cables that are best for long runs from your 4K source rack to a 4K projector, these cannot be bent at a sharp angle. While there are right angle HDMI adapters, anything you add to the source-to-projector path could interfere with a reliable signal transfer.

For a given room, all of these factors might limit your choice of projector and screen. And while most projector manuals provide some guidance for setup, particularly the zoom range relative to screen size and throw distance, it isn't always thorough or clear. Always allow for a margin of error in your setup calculations. A dry run is always a good idea; after mounting the screen, set up the projector on a table at the planned setup distance to see how it will work before you mount it to a ceiling bracket.

Forget the Diagonal — How Wide Is the Screen?
It's easy to confuse screen diagonal with screen width, so it's useful to be able to calculate one from the other. Set makers traditionally use the diagonal because it's a bigger number. But for a projection setup I find screen width more useful — if for no other reason, you'll need the width to determine if the screen will fit the wall you've chosen for it! And even projection screen makers aren't always clear as to whether their specs relate to diagonal or width. I've run the numbers, and for the most common screen aspect ratio, 16:9, the conversion formula is Diagonal x 0.87 = Width. For a wider CinemaScope-shaped screen, with an aspect ratio of 2.35:1, the conversion formula is Diagonal x 0.92 = Width.

Just how big a screen do you need? Five years ago, when HDR wasn't a consideration, this was easier to answer. But for a given projector setup and throw distance, the brightness of the image will vary with screen size. The smaller the screen, the brighter the image, all else being equal. And since you'll want as much brightness as possible for those HDR highlights, it might be worth considering a slightly smaller screen than your gut craves.

To help with this, a number of screen distance calculators are available on-line. The one I've used for years is myhometheater.homestead.com. For a 12-foot seat to screen distance, and a 10-foot wide screen, the viewing angle is 45-degrees. That is, the screen will cover 45-degrees of your field of view. But the THX viewing angle recommendation is 36-degrees, which for that screen size requires a seating distance of just over 15-feet.

Where Do You Like to Sit in a Movie Theater?
A lot depends here on where you like to sit in a movie theater. If you're an up-front kind of person, you may be happiest with that 10-foot screen at 12-feet away. But if like me you're a slightly more than halfway back kind of guy or gal you may be happier with the setup I use — a 96-inch-wide screen viewed from about 11-feet. For a given projector and screen, the latter will offer more impressive HDR.

But also keep in mind that the calculator mentioned was designed for viewing an image resolution of 1080p. For a 4K projector you can sit a little closer and perhaps see a bit more detail. But I wouldn't take that too far, as most of today's program sources are still native 1080p, and most 4K projection is simply upconverted from 2K, either in the projector itself or at the source (most UltraHD 4K discs begin as 2K masters upconverted to 4K in the production process).

You'll also need to make certain that the height of the mounted projector and the screen are compatible. Most projectors have a throw angle designed to accommodate a projector that's mounted at or higher than the top of the screen, a typical arrangement. Most projectors also have a vertical lens shift that can move the image up or down to align it with the screen. But a few projectors offer little or no vertical lens shift, and I don't recommend them for a quality installation. You don't want to have to tilt the projector downward to align the image with the screen. That will make the picture off-square, and the only way to correct for this is to use a feature called keystone. The latter can reduce image resolution. The reduction may be small, but you don't want to go there.

Where to Put the Screen
You'll also need to decide how high to mount the screen. I prefer the center of the screen to be at roughly eye level. Having to look up at the screen can be tiring (and don't get me started on the "TV over the fireplace" abomination beloved of interior decorators everywhere). But be careful if you have a room with a very high ceiling. You may need to use a long extension for the projector mount to get it low enough to fit within the range of the projector's vertical lens shift, a situation that usually calls for professional installation.

There's more of course. If this is an all-purpose room you'll likely want to choose a retractable screen. And throw in a few extra chairs when guests are coming, or have more than one row of seating (an option more practical if the room will be a dedicated home theater). There's also the type of screen (solid, perforated, woven, screen gain, light rejecting — whew!). Some 4K projectors can do HDR better than others, and not all 4K projectors can approach the full range and depth of colors available from 4K source material — some, in fact, are limited to the Rec.709 color range offered by ordinary HD (color is an extremely complex subject that in itself could fill several books — and has). Then there's the topic of short-throw projectors.

But for all of that, and since this blog is already my longest ever, I'll leave you hanging until next time, when I'll get to these and other matters. Did I mention that this video projection business can get complicated? Yes, it does, but when done right it is more than worth it.