What is a Lumen? Why does a lens matter?

When companies call us for a corporate event and need a video, slide show or power point presentation shown at their event, they usually just ask for a projector and a screen. Some of our customers know the difference, but others haven’t the slightest idea of what goes into the type of system they could get. So the next series of blogs is going to go into detail about the common nomenclature of the A/V world, specifically, screens and projectors.

We are going to start with projectors. Projectors are always rated first on how bright they are. So, when you see the term “lumen,” that is telling you how bright the projector is. The higher the lumen output, the brighter the image will be. And, as you can imagine, the higher the lumen output, the higher the price. Most professional projectors range from 2500 lumens to 10,000 lumens. The projectors you see at concerts can be upwards of 100,000 lumens. The most common lumen output you will see would be in the range of 4500-6500.

The higher the lumen output the better the picture will be. The blacks will look better, the contrast ratio is typically higher and the image, most importantly, will be easier to see. It really comes into play with the general lighting in the room. If you are having an event where you expect the lights on, or it may be in the afternoon in a venue with a lot of windows, a high lumen projector will be necessary. When I say high, I mean at least 5000 lumens. You don’t want your client to be complaining that it isn’t bright enough. Ultimately that will be what happens.

The next thing you need to know is the projection distance, or how far you have to “throw” the image. In most cases you will project the image onto a screen, and that screen is relatively close to the projector. But in our world, we need exact measurements to make sure we fill up the whole screen. That’s where the lens comes in. Lenses are sometimes called “glass.”

The lens, or glass, will allow you to “throw” the image very wide if you are extremely close to the screen or keep it very tight if you are far away from the screen. Both wide angle and short angle lens's can get expensive to rent. And those lenses tend to need a higher lumen projector. So knowing where the screens will go, in relation to where the projector will be are very important to us. All lenses are numbered. The number is what tells you the distance you can be from the screen to fill it completely. For example, a 1:1 lens means you have to be 12 feet away to fill up a 9x12 screen. Pretty simple.

So now you know a little more about projectors. Next up will be the screen! As always, any additional questions you have, don’t hesitate to call Matt or Michael and they will help you through the process.

-Jason