Many people have been waiting for high PPI monitors for a long time. There’s a brief period a few years back where laptop companies offered WUXGA 15.4 inch screens, but it appears those monitors proved unpopular among the general population who still had to deal with tiny fonts in windows.
The poor man’s way of making your monitor seem like it has greater resolution is to sit farther back from the surface of the screen. But how much farther back? Well, let’s do a little math.
The equation in the diagram relates PPI, distance from the screen, and the angle of the arc covered by a single pixel in your field of vision (theta). For two different configurations, if the value of theta is equivalent, the percieved PPI of a screen should also be equivalent.
Here are a few set of values that I calculated:
| X (in inches) | Y | theta (in degrees) |
|---|---|---|
| 18 | 96 | 3.315 e -2 |
| 18 | 200 | 1.591 e -2 |
| 36 | 96 | 1.651 e -2 |
| 18 | 150 | 2.122 e -2 |
| 28 | 96 | 2.131 e -2 |
96 PPI and 18 inches is a pretty standard setup. I tried doubling either the PPI or the distance to see what would happen, but as you can see from the equation, since X and Y play both equal parts in the denominator, doubling either variable produces the same effect.
The last two rows I used to figure out, how from on a 96 PPI monitor would I have to sit to percieve 150 PPI.
So I’ve tried pushing my screens back at work to see how it works out. I don’t have a tape measure so I can’t be exact about the values, but there seems to be a positive effect so far. However, there’s also something very jarring about reading monitors that are so far away. I’m not sure if my eyes are just not accustomed to it, or whether humans have a natural reading distance for small text.
But the whole point of this was to see if it would make the color fringing on my Ubuntu-rendered subpixel anti-aliased text less noticeable, and it seems to at least partially have that effect.
Update I left out a critical step in simulating the high DPI experience.. which is to adjust your font sizes. In Gnome this is easy, just go to the font control panel, hit “Details” and then set the DPI to a higher value. This should get reflected in most of your apps. Without doing this, you’re essentially just looking at really small text. If you double your percieved DPI without modifying the fonts, then you essentially made your 8pt font now look like a 4pt font. Doubling your font DPI setting will make your 8pt font 8pt again, giving it twice as many pixels to render with.