HDMI,DVI-D,DVI-I, VGA,RGB,RGBHV… What do they all mean to me? Which should I concentrate on? Is one better than the other? If you have begun working with video lately, the names may have changed but the same principles apply. Now you also may ask the question, What about composite and component? Oh yes, they are still in use. The AV industry just added a few more options.

So let’s look at what these new and not so new cable types are. First, we will look at VGA. This has a 15 pin connector that is often referred to as HD-15 or DB-15. The most common use for this type of cable is to connect your computer to your monitor. This was the first means of connecting computers to projectors. The length of cable you can use is directly affected by the resolution you use. For example, if you are projecting an image at 1024×768@60Hz, the maximum recommended length would be 10 meters or 32 feet. Now, the longer length of cable you use, the more resistance and signal loss you get which translates into noise in your video. I recommend the use of a signal amplifier or distribution amplifier if you plan to mount your projector in the ceiling and use more than 50 feet of cable.

The next type of cable is known as DVI. Often referred by the type of signal it passes, they are called DVI-A, DVI-D or DVI-I. So what does that mean? Well, DVI was the first on the scene. It is now referred to as DVI-Analog. DVI-A cables are used to carry a DVI signal to an analog display(CRT or cheap LCD). In this configuration, DVI-A carries the same signal as a VGA cable. Then there is DVI-D. This is used to directly connect two digital devices, traditionally a video card and digital LCD. DVI-I is the most versatile of the bunch. This type is capable of sending an analog to analog or digital to digital signal. Keep in mind that DVI is not interchangeable. You must use the correct DVI cable to connect your devices.

Ok, we have touched on the most common ways of connecting your computer to a projector, VGA and DVI. Let’s discuss the various ways of getting video signal to your projector or display.

The newest player on the field is HDMI. It is primarily used for HD devices such as HD LCD panels and plasma screens. DVD is the primary device that is connected to these screens and the HDMI cable is capable of sending audio as well so only one cable is needed for both your audio and video signals. The down side is that DVD, HD-DVD, and Blu-Ray are the only devices that have a HDMI port. Computer manufacturer are adding this interface to some laptops but it is still rather sparse.

One lesser known way of getting your computer signal to your projector is known as RGBHV. This is a series of 5 cables that passes the three main colors of video and a horizontal and vertical sync pulse usually terminated in a BNC connector. This type of cable traditionally carries a computer signal to a projector instead of a VGA cable.

A smaller signal such as video does not require the same number of cable connectors as a digital or computer signal does. Therefore, we can enter the world of RGB or component video. This has become a bit more mainstream with the use of DVD players as you found yourself connecting the red, green, and blue cable from your DVD player to your TV that had a component input. It’s still pretty basic but the video signal is divided into three colors so that more information about each can be transmitted to the display device. If you are sending video a long distance or just want a better overall picture, then RGB is the way to do it.

Lastly, there is the composite video signal. This signal can’t be used to transmit a computer signal without a scan converter and only has one small cable. It is the same type of cable used by the TV cable companies. It has every signal transmitted on one cable. Signal quality is ok but should be the last resort used to send video to your projector is you can help it.

Well, I hope this helps you decipher some of the alphabet soup that is video cables. It’s been a while since we have posted but thanks for reading and good luck in all you do. Email us any questions or comments you may have.

Video projection has come a long way from the days of thirty thousand dollar LCD projectors. There are several options to do what your pastor wants. You can go to your local national office supply store, insert Depot, Max or Staples here, and pick up an inexpensive projector but then what do you do?

Is it capable of being ceiling mounted?
Where do you purchase a ceiling mount?
What are your options?
What size screen should we buy?

Let us talk more about these questions a little later. Right now, we should discuss what the specifications mean to you. Lumens, throw distance, and resolution are all important things to consider. A foot candle is the amount of brightness of light at one foot from the source. Lumens are the unit of measurement of light and describe the amount of light provided at where you want to light. Lumens are the way you rate a projector. The amount of natural light in your worship center or other locations will assist you in determining how many lumens are necessary. A small conference room with no windows could use as little as 1200 lumens while a worship center with windows on each side should have no less then 3000 lumens. The larger amount of lumens, the greater the price of the unit will be.

Throw distance is the next item to consider when choosing a projector. The throw distance of a projector is the distance your projector can adequately maintain the proper illumination of the screen at a proper screen size. Projectorcentral.com has a great throw distance calculator that has most models of projectors and screen sizes. It allows you to put in the make and model of projector and it provides you with an adjustable throw
distance based on your screen size.

Resolution is the last of the three things to look at when choosing a projector. Most computers are now at least 1024 X 768 and more laptops are adopting a 16 X 9 aspect ratio for screens with a resolution of 1280 X 1024. This is simply the amount of pixels available on screen. The more pixels, the higher quality picture you have projected. Do not limit yourself by purchasing a projector with a top resolution of only 800 X 600. You should look at a projector capable of at least XGA capability. The screen resolution will also help determine the screen size and aspect ratio.

So now that we have determined how bright the projector needs
to be, how far away, and the screen size. The next questions to ask are:
Where will I mount this?
Can I mount it on the ceiling or will a table be an appropriate height with no one walking in front of the image?
The worst thing to create interference in worship or during a sermon is to have a large shadow appear on your screen. Mounting the projector on the ceiling is always more advantageous than on a table. It is generally more secure and can usually
eliminate the possibility of having someone interfere with the image.

This is where we bring in the second item of consideration for a projector, throw distance.
Is there a good spot at the right distance to place a mount for the projector on
the ceiling?
Is there a light fixture or ceiling beam that obstructs the projection of the image?
How high do I need to hang the projector so that heads are not seen on the projection screen?

In public areas, the rule of thumb is the higher the better within reason. You want the screen image to be high enough to be seen but not enough that the front row has to crane their necks to see the praise chorus or sermon outline.

Now that we know where to mount the projector, what screen size and how many lumens, we can decide what brand to use. So what brand do you use? Well, there are many brands to look at. Sharp, Sanyo, Barco, and Panasonic are but a few brands. They are among the largest and have good reputations. There are models that are consumer level and models that are created as professional. The consumer models tend to be cheaper but usually don’t have the same warranty as the professional models. Unless you can only afford a projector from Office Depot, buy it from a reputable AV integrator.

Well, that should do it.
As always, if anything is worth doing, it is worth doing well. To that fact we can add, if it’s worth doing for the Lord, then it should be our absolute best! Take care and email us if you have questions or comments.