Setting Up a Room for Front Projection


So you have a room that you want to put a projection system in and it is time to start thinking about how it's going to fit into the room. Where do you start?

Step 1. How high is your ceiling?

This may seem like a strange place to start, but your ceiling height controls screen height, which controls screen width, which controls how far back your projector must go, and ultimately, how far back you'll need to place the seating in the room. Here's why.

Any screen you put into your home theater really should start at least three feet off of the floor. This will allow the audience to be looking up slightly — like in a real theater - and will contend with any potential visual obstructions such as a coffee table.

Image Placement

Next, take your ceiling height, subtract three (3) feet from it and you'll have your maximum screen height. This height might be larger than what you want, but it will give you an idea of how big of a screen will fit.

Step 2. What aspect ratio screen do you want?

After you find out the maximum height of your screen area, it is time to figure out the maximum width. To do this, you will first need to decide if you are going to install a 4:3 aspect ratio screen (if you are using the projector predominantly for non-HDTV television viewing) or a 16:9 aspect ratio screen (for movies and HDTV).

If installing a 4:3 screen, take your maximum screen height and multiply it by 1.33 to find your maximum screen width

If installing a 16:9 screen, take your maximum screen height and multiply it by 1.78 to find you maximum screen width.

Presto! Now you should have a maximum screen size.

Step 3. Think about the screen-type and placement.

Next, you will want to figure out what type of screen you want. Do you want a screen permanently mounted to the wall or a screen that can move up and down?

You will also need to think about placement of your speakers. You will need to have three speakers placed around the screen for any surround sound system. Do you have room on the sides of the screen? If not, you will have to think about using a smaller screen.

Speaker Placement

Step 4. Projector placement.

Now that you have a basic idea of what your ideal screen-type will be, it is time to find out if the projector you want will work in your room

First, find out your projector's throw ratio. Multiply the screen width by both throw ratio numbers and you'll have the maximum and minimum distances your projector needs to be placed from the screen. For example, you figured out that you can have a maximum screen width of eight (8) feet for the 16:9 screen you want to place in your room. You think eight feet might be a little too big, so you decide a 7 foot wide screen would work better. The projector you want has a throw ratio of 1.8-2.2:1. So, 7.5 feet * 1.8 equals 13.5 feet, and 7.5 feet * 2.2 equals 16.5 feet, as is indicated in the example below.

Throw Ratio Example 1

Next, make sure your room is set up so that you can place a projector in that area (either using a ceiling mount, a stand or a coffee table).

Step 5. Projector placement Part 2.

The next part of projector placement is figuring out if you are going to ceiling mount the projector or table/stand mount it.

A projectors lens is set up so that the projected image will actually appear above the projector itself as shown in the following example.

Projector Placement
Projectors shoot their images "up"

Because all projectors shoot "up" with their standard lenses, they must be inverted to avoid shooting the image into the ceiling as shown in the next example. Projectors with "lens shift" are able to move the image they create up and down, thereby enabling them to be mounted near the ceiling without inverting the projector.

Incorrect Ceiling Mounting  (wrong image shown currently)

Proper Ceiling Mouting

That said, if you are planning on mounting your projector to the back wall on a high shelf, you must figure a way to invert the projector and hang it under the shelf, or purchase a projector with lens shift.

Step 6. Viewing distance for you audience.

The last thing to consider is where your audience is going to sit. This all is dependent on your screen width, resolution of the projector you are planning on using and what technology you are using

Viewing Distance

Micro display technologies are all fixed resolution devices, hence the images are actually made up of tiny individual elements called "pixels". If you stand of sit too close to the projected image, you will actually see the individual elements, effectively destroying the illusion of a seamless image.

The distance from the image that you need to be, in order to view a seamless image, varies for each technology; it even varies with the resolution of the projector you are watching. Simply put, the higher your projector's resolution is, the closer you can sit to the image.

We suggest the following:

  1. If you have an LCD projector with 600 or less vertical lines of resolution (800 x 600 or 854 x 480), a viewing ratio range of 2-3:1 (V/W) is optimal. If you sit closer that two (2) times the width of your screen, you will start to see the individual picture elements, or a grid pattern known as the "screen door effect," which gets its name by its resemblance to a screen door having been placed over the image. Conversely, if you sit farther away than three (3) times the width of the screen, the "home theater" effect will be lost.
  2. If you have an LCD projector with more than 600 vertical lines of resolution, we suggest a viewing ratio between 1.8 - 3:1
  3. If you have a DLP™ projector with 600 or less vertical lines of resolution, we suggest using a viewing ratio between 1.8 - 3:1
  4. If you have a DLP™ projector that has a resolution of 1024 x 575 or 1024 x 768, but use it only in 16:9 mode, we suggest using a viewing ratio between 1.6 - 3:1
  5. If you have a DLP™ projector that has a resolution of 1280 x 720, we suggest using a viewing ratio of between 1.4 - 3:1
  6. If you have an LCoS projector, your resolution is going to be above 720 lines, guaranteed. We suggest using a viewing ratio between 1.4 - 3:1 Step 7 (if necessary). What happens if the numbers aren't working for me?

    In many cases the numbers you get aren't going to work. So what to do?

    Here are some helpful suggestions for some common problems that arise.

    1. My projector won't produce an image large enough to fill the screen I want to use.
      1. Consider moving the projector farther from the screen (if possible).
      2. If moving the projector back isn't possible, consider purchasing a similar model projector with a shorter throw ratio.
      3. Some projectors have an optional lens that enables the projector to be moved closer to the screen. This is a very expensive option.
      4. The last resort is buying a smaller screen. You must make sure that the new screen size will still be large enough for the viewing ratio calculations.

    2. My viewing distance is shorter or longer than what you suggest.
      1. Our suggestions are only guidelines; if your ratio is close but not too far off from our suggestions, you should be fine.
      2. If your viewing distance is too far, we'd suggest moving your seating forward if possible.
      3. If you can't move your seating or make your screen larger and you are farther than a 3:1 ratio for your viewing ratio, we suggest either rethinking a front projection system, or resign yourself to the fact that you won't be getting the home theater experience you might have hoped for.
      4. If your viewing distance is too short, we suggest moving your seating back if possible.
      5. If your viewing distance is too short, we suggest using a smaller screen if possible.
      6. If you can't move your seating or make your screen smaller and you are much closer than the viewing distance we recommend, we seriously suggest either rethinking a front projection system, or purchasing a rear projection television, plasma screen, or large LCD television.
    3. I need to ceiling mount my projector but I have a really high or slanted ceiling.
      1. There are mounting options for every kind of ceiling. Call us and let our account representatives walk you through determining what you might need.

    If you have questions not covered in this section, don't hesitate to call us.