Today another eulogy was given to AV technology. As with most AV eulogies, the problem is that the technology declared dead is still alive and well. In this instance, the projection screen business was “buried alive” by Gary in his latest blog “Is the Screen Business About to Disappear?” However, like Uma Thurman in Kill Bill, I’m about to punch through that coffin, explaining why the screen business isn’t disappearing anytime soon.
In full disclosure, I work for a company that owns a screen manufacturer, as well as several other AV product companies. However, my outlook is not based on my manufacturer affiliation, but rather my real world experiences as an integrator and the experiences that end users have.
Gary’s blog puts forth three theories on why screens will disappear. I encourage you to read his whole blog that is linked above, but in short, his arguments are LCD and LED screens are proliferating, interactive displays are gaining in popularity, and that in today’s world, projecting on the wall is just as good. Since the last point is really used in the article as the final death blow, I’d like to address that first.
Projecting on the wall is not a new idea. People have tried it for a long time with varying results. The reason projecting on walls has not displaced the screen business is because it rarely turns out well. Why is that?
Walls aren’t flat.
Show me a wall built by a GC, and I’ll show you the ripples in it. Whether the studs are not flush before sheet rock or the tape and mud seams are slightly imperfect, most walls are not flat. Project on one of these walls and you will quickly see straight lines become curved.
Now Gary argues that projection mapping could correct this and theoretically it could, but these ripples are small and slight. Short throw projectors, like the ones mentioned in the article, exacerbate the problem, as the short focal length means less tolerance for wavy surfaces and enhanced distortion. Projection mapping is great at adjusting for protrusions, corners and other architectural features, but adjusting for these tiny imperfections would be a little more difficult. Now add the cost of that software and programming in each job and you may just find that a screen wasn’t a bad investment after all.
Even if you could map out all of the imperfections from a visual standpoint, there is still an issue with interactive projection, in that the scanning system that tracks the touch interactions needs a flat surface as well for accuracy. Imperfections in the wall of varying depths will create potential calibration issues and a sub-par interactive experience with false touches.
As a final note, I installed an interactive projector in a high-end real estate office in 2011 and projected onto a wall coated with Opti-Rite wall covering that turns the wall into a white board. The wall was not flat and caused the projected image to be wavy and distorted in places, all issues that having a proper rigid, interactive screen would have corrected. Luckily, that projector only used an IR pen for the interactive component, so the issues with a laser scanning, touch-enabled interactive system were not an issue in that project.
Walls aren’t smooth.
Now Gary argues that wall texture isn’t an issue, but physics of light argue differently. If you’ve ever played pool, you know that angle of entry equals angle of exit. Higher resolution projectors don’t solve this problem. They make it worse. As pixels get smaller, the chances of texture on a projection surface reflecting that pixel away from the eyes as opposed to straight back to the eye actually increases. Moire effect also becomes more of a potential issue as texture increases. Speckle in laser projectors has been seen to increase as the texture of the projected surface increases. This is why screen technology has continually gotten smoother with each iteration. The proper screen will mitigate all of the potential negative effects that a textured wall would create.
Walls aren’t uniform.
Uniformity in a projected image matters. If an image has hotspots or varying levels of brightness, the quality immediately suffers. This applies to LCD and LED displays, video walls, and arrays as well. Go look at a video wall that has not been properly calibrated and you will instantly see this is true.
A painted wall may seem like it has even coverage, but shine some bright light on it and you will immediately expose the truth. You will see where the paint is applied unevenly, where there are thicker coats of paint than in other parts of the wall, and even where the mud and tape seams may reflect light differently than where the paint is just on the sheet rock. The resulting image can look splotchy and striated.
As an integrator, I once did a job where we built a simulator. It used a 6-degree of motion platform (like Star Tours at Disneyland) and utilized a 30,000-lumen projector to create the imagery. The client insisted on projecting on their curved wall as opposed to buying a curved screen. The moment the system was powered up, the streaks in the painted wall were immediately visible and the customer did not have time to properly spray the wall (multiple spray coats done horizontally from top to bottom until even coverage is achieved) before the attraction opened. The result was an experience that was less than immersive, something that would have been avoided if the proper screen was used.
Walls don’t reject ambient light.
Ambient light rejection (ALR) is a real thing in the screen world. If you want to achieve contrast ratios in a projected image, you need to be able to reject ambient light. You can’t project black. ALR screens typically have a base gray level that enhances the blacks and the screen has gain properties that keep the colors correct and the whites white. Painting a wall gray will not have the same effect, as paint does not have those gain properties. It will add a base level gray to white and all the colors in between.
Gary asserts that color correction could be applied to address varying wall colors, and that is in theory true. However, a base wall color other than white will change the white levels as well. Depending on the shade of the wall, you may have to add lumens to the projector to get your white levels back, and then color correct for the hue of the paint. Here’s the problem, lumens are expensive. Even if you wanted to use the wall, add lumens and color correct the image, odds are you just spent more money in projector brightness and labor than you saved by not utilizing the proper screen.
There is no wall.
Go into many corporate environments and you will see conference rooms. All of those rooms technically have walls. However, many of those conference rooms are fish tanks with glass walls on all sides. Others have glass walls on the entry side and a window opposite of the entry. In these cases, many times the room dictates that the screen needs to go in front of a piece of glass or in front of a window. When this happens a drop down projection screen may be the only option, as there is no solid wall to project upon anyway, even if all the problems above did not exist.
Now I’m not saying that there aren’t applications where you may want to utilize a wall for projection. There may be. However, those walls should be purpose built so that they are flat, smooth and painted evenly with a white paint to help assure that the images are correct and acceptable. These would be purpose built spaces, not places where projectors are just added to an existing room as an afterthought. Even then, a system where top and bottom pre-leveled tracks are installed to the wall and then projection material stretched between those tracks would create a better surface.
As another point on this, a large amount of manual projection screens are utilized in schools, and these screens pull down in front of charts, maps or chalkboards which means the wall is not free for projection even if you wanted to utilize it.
LCD and LED Proliferation
I won’t spend a lot of time here, as Gary concedes that large venues or rooms where screens need to be larger than 100″ in diagonal will still need projectors. If LCD and LED aren’t killing projectors, then they aren’t killing projection screens either.
Price per square foot of the screens, installations where the existing structure can’t support the weight of a video wall, complexity of mounting solutions, etc. may all preclude LCD and LED in many installations.
In all of these cases, a projector and a screen will still be the preferred solution.
There is no doubt that there is a renewed buzz around interactive displays, especially with the introduction of Jamboard, Surface Hub and Spark. But here’s a little secret.
Interactive displays aren’t new.
Interactive displays are being utilized more, but those sales will affect traditional flat panel sales as much if not more than they will affect the projection screen business.
These interactive displays top out at 84″ right now. In rooms where larger screens are needed, these will not kill projection screens. In the hierarchy of importance, visibility trumps interactivity. What good is an interactive display if no one can see it? In these cases an interactive projector will be used instead and because of the issues above, a proper screen should be utilized to assure video quality and interactive accuracy.
Here’s another secret.
Interactive displays aren’t cheap.
Don’t get me wrong, interactive displays are worth the money when the application demands it. I used to work for an interactive display manufacturer so I know the benefits and applications well. However, I also know from my experiences selling them, that in areas where no interactivity is actually needed, they will not be purchased just because they are cool.
Interactive displays are built for small rooms with viewers and participants that will stand close to and touch the screen. This is not the traditional application for most projection screens anyway.
The projection screen market IS changing.
So, all of the above being said, I’d be remiss to recognize that the projection screen market is changing.
Flat, rigid, writable projection screens are taking the place of traditional pull down screens in front of white boards as more interactive projectors enter the market.
Transparent and translucent projections screens or projection films are finding more applications in digital signage applications like window displays and mediatecture due to the capabilities of laser projectors to run without bulb replacements and in new orientations.
Ambient light rejection screens are allowing projectors to be placed in brighter environments to maximize brightness and contrast without compromising screen size.
Specialty projectable paints and wall coatings or fabric wall systems will be incredibly important as more immersive AR and VR environments are created.
However none of these shifts spell death. Technology always changes and applications shift. It is our AV reality.
If you don’t mind having a washed out, splotchy, patterned, wavy image that needs to be corrected for color and geometry, has reduced interactive accuracy and screen resolution and requires a brighter, more expensive projector to restore white levels… then by all means, use the wall. Heck, maybe the bed sheet will kill the projection screen business too.
I’ll declare projection screens dead when large format OLED film can be applied like wall paper to a wall or rolled up like a drop down screen at a reasonable price.
Until then, you may want to invest in a projection screen.