How does screen resolution work? And why does making things bigger (physically) make things smaller (in pixel count)?

Often when clients get nice new fancy computers or even just bigger screens they're disappointed to see things are in fact SMALLER, not bigger at all, why's that?

Screen resolution seems like a very simple thing, and most of the time it is.

The problem is sometimes it's not. And it's not in a way that let's me say "smaller is actually bigger" with a straight face.

Yes, making things smaller can make things bigger.

Told ya it'd be complicated.

We'll start with your computer display or screen or as it's more commonly called the "monitor" (because in the old days it was where computer

operators monitored the operations of the room-sized computer).

Your monitor is comprised of "pixels" - individual dots - that are arranged in a rectangle. Each is one point of light and that one point of light is capable of being a color - any of hundreds of thousands or millions of different colors, in fact.

The dimensions of the rectangle of pixels on your monitor is it's maximum resolution. For example, the monitor I'm looking at is 1920 pixels wide by 1200 pixels high - a little over 2.3 million pixels:

Windows, of course, allows you to configure the screen resolution that it displays as. This is independent of, but limited to, what your monitor is actually capable of. For example, attempting to display something larger than 1920x1200 on my monitor will likely result in no output at all - my monitor is incapable of displaying anything larger. (Your video card represents an additional limitation, but I'm explicitly ignoring it here, assuming that it is more capable than your monitor, which is frequently the case.)

The ideal setting is typically to set Windows to display at your monitor's maximum resolution.

This is the ideal setting because as we'll see in a moment, there's no scaling or stretching. Your monitor has exactly one pixel at each point Windows is expecting there to be one. The monitor's physical characteristics match what Windows is attempting to output.

So far we've seen that the ideal setting for most is to match exactly your monitor's capabilities, and that if you try to display something larger, in terms of pixel count, then you may get nothing at all.

What happens if you display something "smaller" in pixel count?

I'll use 1024x768 as my example:

When you use Windows at this resolution, things get more cramped:

Windows that were, perhaps, 1000 pixels wide now take up most all the available space on the screen.

When you attempt to display 1024x768 on a monitor capable of larger resolution, like 1920x1200, several different things can happen.

Centered: the 1024x768 display that Windows is trying to create might be centered in the 1920x1200 physical screen:

This will typically feel smaller, as only a portion of the displays physical screen is being used. This is fairly rare among computer monitors, but it can happen. I've seen it more often in older laptops, particularly at boot time when Windows attempts to display an 800x600 screen on a laptop monitor typically much more capable.

Proportional Stretch: the 1024x768 display is stretched to fit the physical area, but while maintaining the original ratio of height to width (the "aspect ratio"):

This is extremely common behaviour for monitors that are asked to display a resolution less than their maximum.

One thing to note, however, is that sometimes what's on the screen can seem somewhat fuzzy. The issue is that what was intended to display as a single pixel on, say, a 1024x768 display is now "stretched" over more than one to expand into some portion of the 1920x1200 monitor. Depending on the specifics and how you calculate it, this example attempts to stretch 1 pixel over about 2.4 pixels. Since partial pixels are impossible, fuzziness results.

Perhaps the most remarkable point, however, is the most confusing: Because the smaller image has been stretched to fill a larger physical area it appears larger. Compare the Internet Explorer

Window in 1920x1200 native on the left to the Internet Explorer Window in 1024x768 stretched and centered on 1920x1200 on the right:

This is the part where I get to say - with a completely straight face - that making your screen resolution smaller may in fact make appear bigger on your display.

Stretch-to-Fill: the 1024x768 display is stretched to fit the physical area, but the ratio of height to width is not preserved.

What you might notice here is that everything looks ever so slightly elongated horizontally.

What's happened here is that the image was stretched vertically, taking what was the 768 pixel height of the displayed screen to fit the 1200 pixel height of the monitor. If you apply that same ratio (3/4) to the width, you have only 1600 pixels to fit on a display that is 1920 pixels wide. Where in the prior example we simply centered the result, displaying gray or black bars on either side, in this example we stretched that 1600 out to 1920 without changing the 1200 pixel height. The result is that while the image fills the entire monitor, it appears horizontally elongated.

The bottom line is that "making things bigger" can mean either of two things:

• Increase the resolution, adding more pixel to your screen and giving it a logically larger surface area as measured in pixels.

• Increasing the size of something on the screen, making it visibly bigger.

As you can see, there are many approaches, and yes - making things bigger (physically) by making things smaller (in pixel count) is in fact one of them.