Why does high definition become more important as your screen gets bigger

There’s nothing like a big screen when it comes to home theater.

Projection screens have a minimum diagonal of 80″ in 16:9 format these days. That’s quite a bit bigger than the average plasma or LCD TV.

To create a bigger image, the source image is enlarged by the projector. So if the source image has only a few pixels, these are blown up to create the larger image.

Why images can look great on a small screen, but horrible on a big one

Here’s an example of an image on a small screen:

Now, if you would look at your projection screen, the same image would look like this:

As you can see, each block has increased in size and so has the distance between the blocks.

Now, the lower the resolution of the image, the greater this effect will be. The result, a grainy image.

A high definition image has a lot more “blocks” (pixels) to create the image. This means they are closer together and so, when the image is enlarged on your big projection screen, it’s a lot sharper than a non-hd image.

So that’s why a DVD that looked great on your regular TV all of a sudden looks disappointingly bad on a large screen.

Now, let’s put this in perspective by showing how big a projection screen can really get.

Numbers don’t say as much as images do, so here’s a comparison (to scale) of how a 42″ flat screen TV compares to a projection screen

So now you see just how much bigger the surface of a projection screen is than the one of a flat panel. And this explains why HD becomes more important as you move to a bigger screen.