Church Projection System Design: Location, Power, and Cables
1. LOCATION: Don't forget that you have to figure out how and where to mount, power and run cables for your projector. What you WANT to do and what you HAVE to do may be dramatically different. Another reason to rent or borrow a projector and try it out in your auditorium or classroom is to determine where you will mount your projector. Set the borrowed projector on a stand and move it closer and farther away from your screen to determine what the best location is. I recommend that you don't locate it with the zoom set all the way in or all the way out. Set the projector where you have left some room to allow the screen to be made both larger and smaller with your zoom lens. This may help you later if you decide that you need to increase or decrease the size of your image when you mount it. It also is typically the best optical spot on a zoom lens. Look straight up at the ceiling where from where you have placed your projector on the cart. This is where you will mount it on the ceiling. Plan to mount the projector upside down on the ceiling above the location set on the floor.
Your projector manufacturer also has a chart to show "throw distance" if you want to calculate where your projector is placed.
2. ELECTRICAL SERVICE: Where you mount your projector you will have to get electrical power to it. Plan to hire a qualified electrician to run the power for your projector. You will need to adhere to all electrical and construction codes and may even need a permit to install the outlet. Likely, you will need the wiring run in conduit and you may need a new circuit in your circuit breaker panel. Putting it on a separate circuit may help reduce potential electrical interference problems.
3. SIGNAL CABLES: You will need to get signal cables from your source to your projector. Plan to buy long, low signal loss, good quality cables. For many churches, running the cable is one of the hardest parts of the installation. Cables can be difficult to hide. Bad cables are often the cause of interference or a bad image. Don't skimp on cables. Go ahead and run ALL the different kinds of cables that you may need. Read your projector manual carefully. You will probably need to put in cables for computer video (VGA), S-Video and RCA (Phono) video. You may need to run a USB and or Serial cable to the computer for control. It is often a LOT easier to run them all at once in the original install than to add them later on. DO NOT run your electrical power wiring and signal wiring in the same conduit. In addition to being dangerous and against electrical codes, you may induce power line interference into your signal cable. In fact, it is best to run your signal cable in a route that is perpendicular to your power cable.
4. CABLE DISTANCE: I am often asked about how far you can run cables. I have had a lot of success at up to 100 feet of cable of nearly every type (RCA, SVideo, VGA, etc.) when using high quality, low loss cable. Try buying the cable and seeing how it works. You can always add an amplifier later if you need one. Sometimes amplifiers cause problems instead of solving them. You can actually OVER-amplify a signal and create a bad signal. Another common problem is that some computers (especially notebooks) may not "sense" the projector through the amplifier and shut down the external video port.
Don't forget...this design info is for a SIMPLE system such as a small auditorium so 100 feet should be plenty of length for your design. The bigger and more complicated your system the greater opportunity for failure.
WARNING: Running your cable a long distance can result in the dimming of your image. Try running your projector from a short cable and check your image brightness. Then try your long cable to see if you get image dimming. If you image is significantly dimmer then you will need to either get a better quality cable or add in a VGA signal booster (amplifier) If you split your image to go to two projectors then you most likely will greatly dim your image and you really should consider a VGA signal booster.
Physical Considerations
1. LOCATION: In the section about Power and Cabling we talked about how you should set your test projector up on a stand to figure out where it needs to be located. Again, make sure that you don't set it too close or too far away. Set it at a spot at which you can still zoom out some and still zoom in some. In addition to being at the "sweet spot" of a zoom lens, this will give you some flexibility later if you decide to change your screen size or if you find out when you mount it on the ceiling that things aren't quite what you thought. Plan to mount the projector upside down on the ceiling directly above the location that you set it on the floor.
2. REMOTE LOCATION: A lot of churches want to mount their projector at the rear of their auditorium. Even in a small church this can be very expensive. If your church buys a small, relatively inexpensive video projector then it probably has to be mounted less than 30 feet from the screen. It would be nice to have the projector at the back of the auditorium. This would allow operators to work with the projector without bothering the congregation. The projector can be better hidden at the back and cable lengths can be shorter. The problem is that the relatively inexpensive projectors that small churches like to buy are designed to be used for small rooms and have nonremoveable (fixed) lenses. If you want to throw your image 50 to 100 feet then you are going to need to buy a "long throw" lens. Only the more expensive projectors will accept such a lense. In addition, you may find that the cost of the long throw lens may be well over $1,000 dollars and reduce the lumen rating of your projector. On the other hand you can get a trade off by saving money on cable runs, mounts, electrical installation and make it a lot easier to change bulbs when you mount your projector in the back. You are just going to have to look at your situation and see what is best for your church.
3. SAFETY: As stated elsewhere in this guide, working at height is dangerous. Be careful! A few thousand dollars savings is not worth it if someone gets hurt installing the projector. Spend some money to have experienced high workers mount your system. In addition, make sure that the projector is securely mounted. Even a lightweight projector dropped from a height can severely injure or even kill someone below. TAKE NO RISKS.
4. MAINTENANCE: Even if your projector has a bulb rated to last a couple of thousand hours you are ultimately going to need to replace the bulb. Consider how you are going to get to the projector in the future to work on it, refocus or resize the screen.
5. UPSIDE DOWN: Don't forget that your projector MUST be turned upside down when mounted on the ceiling. A lot of amateurs forget that. Most relatively inexpensive projectors actually project the image slightly upwards. Typically, the bottom of the projector is level or even a few inches below the bottom of the screen. If you don't turn your projector upside down part of the image will shine on the ceiling. If you tilt it down enough to shine on the wall then the image will be distorted. This is called the "keystone" effect. Some computers have a built in digital keystone effect correction but try to avoid using it. It does result in some image degradation. This is kind of hard to explain. The bottom line is that in virtually every small church setting if the projector is going to be mounted on the ceiling then the projector must be turned upside down. There are only a few odd installations in which this is not true.
Virtually all projectors have a setting that allows you to invert the image when you mount the projector on the ceiling. Check to make sure that your projector has this feature.
Since you are going to hang the projector rather than sit it on a ledge or platform at the ceiling then you probably need to buy a ceiling mount from the manufacturer. You may be able to save money by buying a generic mount. Typically, these mounts allow you to make some minor adjustments in aiming the projector. It also can help toward safety. As warned several times in this guide you don't want your projector to fall and break or worse, injure someone.
You need to figure out how far down from the ceiling you will hang your projector. In general, the projector will need to hang down from the ceiling until it is nearly level with the top of the screen. You need to plan for this in your design. You may have to buy an extension pole for your mount.
Be aware that in most installations, your projector basically needs to be set level and perpendicular to the screen. If your projector is not reasonably level and perpendicular to the screen then you may get a distorted image. A distorted image not only looks odd but you won't be able to focus the entire image. You will have to choose whether the center or one side is in focus, the other parts of the screen will be out of focus. As explained several times in this guide, this plan is for a simple design. Odd installations may need professional help.
