A question we get often here at ARC is on the topic of projectors, “I need a projector, which is the best one?” Although this may seem like a good question to ask, what you should really be inquiring is, “How do I choose the right projector for my specific needs?”
To this, there are 2 main considerations when choosing a good projector:
1) Throw Distance – How big the image needs to be at a given distance from the projector.
2) Lumens – How bright is the projector at that given distance.
These two specifications will determine the type of projector you need with regards to Throw Ratio.
What is throw ratio? Throw ratio is the (D)istance from lens to screen divided by (W)idth of the image that will be projected. D/W = Throw Ratio
Example 1: You know what screen size you want, but need to know how far back the projector will need to be placed.
If the screen width (W) is 7 feet and the projector’s throw ratio is 2.0 – 2.4:1 (because projectors have zoom lenses, they also have a range of throw ratios) then you can place your projector anywhere from 14 to 16.8 feet away from the screen. (7 * 2 and 7 * 2.4 = 14-16.8)
Example 2: Maybe you don’t know which screen size want, but you do know that the space available in your room for projector placement is limited.
The projector should be placed 15 feet away from the screen. So, how big of a screen can you use? If your projector has a throw ratio of 1.8 – 2.22:1, your screen can be between 6.76 and 8.33 feet wide. (15 / 2.22 and 15 / 1.8 = 6.76 and 8.33)
Additionally, if you know the size of the room and the width that you have for the screen, you can find out what throw ratio you need your projector to have. A room that allows a 12 foot throw to a screen that’s 8 feet wide is 12/8 = 1.5 which is very small and requires a special wide angle lens on your projector.
There are a few calculators to help with determining throw like this one HERE or the PRO version HERE. You can choose the projector you’re using, such as the Canon REALIS WUX450, and see the capabilities of that specific projector.
Armed with this very basic knowledge you can be sure you will get the best projector for your specific needs.