When it comes to size, it’s not the length it’s the gir… Wait. Wrong article. Like so many things in life, when it comes to selecting a screen, size does matter, and there is nothing like being able to casually drop the line, “Yeah, I’ve got a hundred inches,” into every conversation.
Before you shout, “I want a screen SO big, that it will be an affront before the very face of God!” there are a variety of factors that will influence what size screen you should purchase. Things like the size of your wall, your viewing distance, and your projector.
In my experience, the most popular screen sizes are between 100 – 120-inches diagonal as they give a real cinematic experience, fit into most rooms and seating distances, and won’t overwhelm most projectors. But, let’s explore these sizing factors a little further, shall we? (That was rhetorical. We are going to do it whether you like it or not. Settle in.)
Usually wall height is the issue, but you might have a width issue if you are planning on installing a screen between two windows or if you are putting it in a room over the garage that has an A-Frame construction where the side walls angle up and in to the ceiling. If you have some physical wall size restriction, this will likely determine the maximum size of your screen.
A bigger problem will likely be site lines, as in, can everyone in the room see the entire screen.
For most rooms with an 8 to 9 foot ceiling and 10 to 12 feet of width, this likely won’t be an issue. A bigger problem will likely be site lines. As in: Can everyone in the room see the entire screen. With a large screen, being able to see the bottom is often an issue, especially when you are going to have multiple rows of seating. Let’s do a little math, shall we? Let’s take a 120-inch 16 x 9 aspect screen. This measures roughly 59 high by 105 wide. If we add 3.5 inches all around for our nice frame, we are at 66 x 112. An eight foot wall is 96-inches. So if we jam our screen right to the very ceiling, the bottom of the screen image will be at (96 – 3.5– 59) 33.5 inches up from the floor. (We don’t measure the full 7-inches of screen frame because the bottom portion of the frame isn’t necessary for calculating.) Make a line at 33.5-inches on your wall and then sit in the second row of your theater with someone in front of you. Can you see it? If not, you need to go to a smaller screen. Or build a taller riser for your second row. Or just tell the people in the back row to suck it, and to buy their own damn theater if they don’t like it.
Even if your wall could handle the Great Pyramid of projection screens, your eyes probably still aren’t up to the task. Usually the limiting factor will be your seating distance from the screen. In the past, we used to worry about things like seeing scanning lines or pixels, but with 1080p and 2-plus-million glorious pixels of information – not to mention the likely imminent arrival of 4K with over 8-million pixels! – you likely would never see a pixel even at viewing distances that even a front-row junkie would consider insanely close.
More problematic is if the image exceeds what is known as your eye’s subtended viewing angle. (For the math challenged, a subtended angle is the angle made by a line or object.) What this means is that you don’t want to be so close to the image – or have an image so large – that it exceeds what your eyes can take in and you are forced to actively move your eyes (or head) across a large area tennis match style. This is fatiguing and can lead to headaches, which is generally something you want to avoid when designing something meant for entertainment.
However, like all things in technology, there isn’t one “right” answer on how close is too close, and there are two schools of thought on the maximum viewing angle. SMPTE (pronounced “simp-tee” and standing for Society Motion Picture and Television Engineers) feels that the max should be 30-degrees. The folks over at THX (pronounced “tee-aitch-ex” which is part of the name of George Lucas’ first film and rumored to stand for “Tomlinson Holman Xperiment”) feel that your eyes should be tough and take a beat-in La Raza Nation style, enduring a full 36-degrees. Either way, calculating this is tricky with cosines and other weird Greek-looking symbols and fraction thingies, so I just use this handy calculator.
According to the maths, if you have a 120-inch diagonal 16×9 screen you should sit no closer than 16.3 (SMPTE) or 13.4 (THX) feet from the screen. So, if your room isn’t this long, then maybe you should go with a smaller screen. Or buy some Tylenol.
The last piece of the screen sizing puzzle is the projector. That poor thing can only put out so much light, and the bigger the screen, the dimmer it will be. I like to use a MagLite flashlight as an analogy. You know how you can dial down a MagLite’s beam until you get a focused cone of that will sear the hair off of someone’s face? Or you can make the beam into a big, wide circle that throws out a soft, gentle globe of light? Same with a projector; there is one light engine and smaller is brighter and bigger is dimmer. Now, “dim” is relative, as some projectors are frickin’ light cannons that blast out lumens like they are going out of style. Do not believe what you have heard; lumens are definitely not going out of style.
When it comes to understanding projector light output, you are going to read terms like lumens – the amount of light coming out of the projector – and footlamberts (ft-L) – the measure of light that comes off the screen. As a point of reference, those crazy boys at SMPTE came up with another standard, this time called SMPTE 196M, titled “Indoor Theatre and Review Room Projection – Screen Luminance and Viewing Conditions.” This specifies that a commercial theater projector should produce 16 ft-L from the screen. It’s important to note that this is measured “open-gate,” or without film in the projector, and usually drops to around 12 ft-L when the film is being shown.
While there are multiple aspect ratios – 4×3, 1.77:1, 1.85:1, 2.35:1, 2.40:1 – there are basically only two aspects – or screen shapes – that you need to worry about if we’re talking about a home projection screen: 16×9 or 2.40:1. (While 2.35:1 is also popular, it seems that the industry is moving to 2.40:1, and in reality, they are very close in size/shape.)
Deciding which aspect is right for you will depend primarily on what you watch the most. If you principally watch TV, sports or play video games, then you will want to go with a 16×9 screen. That way the full screen area will be entirely filled with an image the majority of time. However, if movies – principally movies on Blu-ray – are your thing, then a widescreen, cinemascope 2.40:1 aspect screen will allow you to enjoy the biggest image possible. (For more on understanding the benefits of anamorphic projection, read my post “Why you should embrace black bars.”
Masking eliminates the white area – or the “dreaded black bars” – around an image and replaces it with sweet, video enhancing, eye-focusing black.
Of course, this doesn’t have to be a one-or-the-other choice. With the magic of technology you can enjoy both aspects, ensuring that you have a giant, cinematic screen when you watch Star Wars VII, and also enjoy the Super Bowl and Survivor without a bunch of white space. The solution is called masking and it is offered as an option by all the top screen manufacturers.
Masking eliminates the white area – or the “dreaded black bars” – around an image and replaces it with sweet, video enhancing, eye-focusing black. The benefit is just like the black frame around the screen; it draws the eye to the active image and improves perceived contrast.
There are primarily two ways to mask a screen. Vertical masking turns a 16×9 screen into a 2.40:1 viewing area, and horizontal masking turns a 2.40:1 screen into 16×9. Again, the right way to go for you will depend on what you want more. My personal screen is a Draper Access/MultiView Series V that is 115-inches when fully opened in 2.35:1 aspect, and masks down to 92-inches at 16×9. Personally I like blockbuster movies like Lord of the Rings and Iron Man to be bigger and more impressive than Teen Mom or Hell’s Kitchen, but if you’re a gamer or a sports nut, you might want those images to be bigger.
Some screens, like Stewart Filmscreen’s Director’s Choice and Screen Research’s X-Mask use both horizontal and vertical masking to achieve any aspect ratio imaginable, so you will have a perfect image whether it is old-school 4×3 TV, 1.66:1 on some Disney animated titles, 16×9 of HDTV, 1.85:1 of Academy Flat, or any of the many scope aspects all the way up to the full-on hardcore, pipe-hittin’ 2.93:1 Ben Hur. However these 4-way masking systems are muy-muy expensive, and that sting you feel will be in your wallet if you decide to get one.
#ProTip: Want to have a masking system on the cheaps plan? Get a 2.40:1 screen and then mask it down with drapery that you manually open/close yourself. This could save you some serious duckets and still deliver an awesome experience, and provide for a very cinematic reveal as the drape opens to show the screen when you’re ready for the movie to start.
No Trouble with the Curve
With more home theaters embracing 2.40:1 aspect projection – either through an external anamorphic lens like the Panamorph DC-1 I use or the zoom-out method – a new type of screen is available from many manufacturers – Stewart Filmscreen, Screen Innovations, Screen Research, DNP, Elite Screens, Draper – that has a slight (usually around 40 degrees) curve. A curved screen offers three principal improvements over a traditional flat screen in that it helps to eliminate pincushion distortion (kind of like a small smile/frown in the top and bottom edges of the image), better wraps the image around your periphery for a more engaging experience, and more evenly reflects lighting back to viewers from edge-to-edge with no hot-spotting for a more perfect picture. When you get into curve screen territory, you are into some serious home theater action so, respect. However, a curved screen must be fixed, not retractable, and generally has a larger frame around the screen and costs more. Also, adding masking to a curved screen can be crazy expensive. But if your wallet is up to the challenge, a curved screen with masking can deliver the most cinematic experience possible.