It's All In the Detail:
How Much Resolution is Enough?
We are in a resolution race, with 8K projectors and content being pushed out by manufacturers in a mad rush to be first to market on what promises to be a highly lucrative market.
However, with many churches and other houses of worship just now making the jump to 1080p and 4K projection, the question must be asked how this new, higher resolution affects current and future upgrade decisions.
To understand whether 4K or even 8K would make sense for your church, we must first explore why higher resolution matters and what difference it can make. Our text and images are created by pixels, and the simplest explanation is that the higher the resolution, the smaller the pixels, the greater the detail and the smoother the edges of lines and curves. However, with higher resolution comes an unexpected danger: a potential loss of legibility with text. You'll notice, for example, that if you change the resolution on your computer to 800 x 600, text and images will be fairly large, because the pixels are much larger in size. However, if you change your resolution to 1920 x 1080, that same text will be much smaller, which makes it more difficult to read.
Of course, this is easily dealt with by the ability to scale up/zoom in within your particular software program, but what if you are using presentation software like ProPresenter? You have one output resolution that you can choose and you are stuck with it. If your on-screen text is too small, your only option is to increase the font size. This may not bother you, but you can quickly run into a situation where on-screen text and imagery are competing for the same real estate.
So is the answer to choose a lower resolution? Well, that depends. Do you want text or images to take precedence? Unlike in times past, churches are not choosing one or the other—they want the best of both of worlds because they need to have both.
The good news is that technology has progressed to the point where you can have your cake and eat it, too. The trick is that you first need to establish how large your screens need to be. I covered this in a previous article, but the basic rule of thumb is to measure the distance between your screen and the seat furthest away from the screen, divide this by a number between 3 and 6, and this will provide you with the preferred horizontal measurement of your screen. This is the recommended method for most people to be able to still be able to resolve enough detail with their eyes before the lines between objects becomes blurred.
Of course, when planning for your screen, you want to plan for the lowest common denominator, so if you want to ensure that those with poor eyesight can still see detail well, you will want to divide using a lower number (e.g., 3 or 4). This should ensure a large enough image for those viewers. However, in addition to a larger screen, you may need to also increase your image resolution. The higher the resolution, the closer your audience can sit to the screen and retain detail. This is an important consideration because resolution does not just scale with the size of your screen; at some point there is a maximum image size at which the projector's native resolution breaks down and individual pixels can be seen. This is one of the critical factors in determining pixel pitch for LED video walls: how close is the closest viewer? Pixel pitch is the distance between pixels on each panel—the lower the pitch, the higher the cost. Bear in mind, there is almost always a trade-off to be found, regardless of display technology.
To throw some numbers at you, based on visual perception a 120-inch diagonal screen at 1080i resolution has a recommended viewing distance of 15.7 feet. For SMPTE (Society of Motion Picture and Television Engineers) standards, the maximum viewing distance is 16.3 feet, and for the THX standard, that number is a shockingly close 13.4 feet. However, in a real world scenario, I can stretch that to around 45 feet if I just increase the font size a little, which is a real-world solution.
But this also brings up one more factor for consideration and that is what I call the "Wow!" factor. This is simply when a house of worship wants to ensure that the images on the screens are more than just supplementary; that they can stand on their own. For situations where the screens must play a more important role, or perhaps play a secondary role such as a movie night event, I will always recommend a brighter projector, a larger image size, and perhaps a step up in resolution. This guarantees that every seat in the house will be able to read text clearly and the imagery will be bright, clear, and vibrant.
In order to choose a projector that fully meets your needs, you'll need to consider a lot more than just lumens or whether you're projecting on a wall or need a screen.
In addition to lumens, resolution, screen size and screen material, you will also need to establish how important highly accurate color representation is for your church. If you are showing mainly imagery and video, having a higher color accuracy in your projector(s) could be a high priority, which means you may want to look at projectors with 3-chips. Of course, depending on the type of imaging technology, this could mean you will pay more per projector.
If you don't need that highest level of color accuracy, there are many projectors on the market that will produce very pleasing and colorful images with a single-chip, and this can save you a fair amount of money.
So finding the projector that best serves you depends on several variables that only you can answer. Many projectors from reputable manufacturers will produce images that will work for your needs, providing that you do your research and understand the factors explained above.
If you are unsure of how to get this information or are simply uncomfortable with trying to find it out, I strongly urge you to contact an AV consultant or systems integrator to do this research for you. While prices for projectors are always falling, churches should not be looking to spend money on solutions that have not been properly designed and/or vetted. Many professionals will provide a free consultation, but you should also be prepared to spend a little money to have them do the system design and engineering for you as that does take time away from other clients. There are huge benefits to be reaped by having your projection system properly balanced for your needs and designed to last for many years into the future.
Finally, there is the oft-mentioned concept of future-proofing your system by choosing a higher resolution than you need right now. Honestly, while there is some wisdom in this practice, I would recommend that 1080p is plenty for the foreseeable future for most micro and small churches or other worship facilities. Larger venues could benefit from higher resolutions for the reasons listed already, but my contention is that most people will not be able to tell simply by looking at your screens whether you are using 4K or 1080p—and if they cannot tell, then why spend more money than you need to? We need to be careful that we are good stewards and not letting pride get in the way of that mission.
Tim Adams is president and chief systems designer for Timato Systems, an audio/video integration company specializing in servicing the sound, lighting, video, projection and live-streaming needs of churches and other houses of worship. He can be reached at firstname.lastname@example.org.