SIMPLE CHURCH VIDEO DESIGN
HOW TO DESIGN A SIMPLE VIDEO PROJECTION SYSTEM FOR A CHURCH: Part 2
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 lense.
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 lense, this will give
you some flexibilty 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" lense. Only the more expensive projectors will accept such a lense.
In addition, you may find that the cost of the long throw lense 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.
Proceed to:
Church Simple Video Design: PART 2.
INDEX
Church Simple Video Design 1 - How to.
Church Simple Video Design 2 - Cable, Power, Location.
Church Simple Video Design 3 - Controls & Lighting.
Church Simple Video Design 4 - Screens & More.
Church Simple Video Design 5 - Common Issues.
Church Simple Video Design 6 - Sample.
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