Originally Posted by ILoveHighDPI
The idea is to have a monitor that produces more detail than you can see.
Open a paint program, draw a straight line, almost flat, form left to right. See the jaggies.
I can stand 9' away from my laptop (15" 1366x768) and still see jaggies (just barely).
That is a "worst case scenario" as far as making jaggies visible, however, if there is any
way to produce a noticeable jagged edge, that means your screen is not giving you more detail than can be seen.
So, technically, if you have a line that is one pixel higher on one side of the screen than the other, and you can pick out approximately where the change happens, you need higher DPI.
Exactly. Human eye visual acuity is much higher than most people think. You are probably correct that you could see jaggies from 9' on that screen...in fact, it's a damn good test for anyone to try.
Do as DPI suggested everyone.
1) Open MS Paint.
2) Draw a horizontal line that is SLIGHTLY not perfectly horizontal.
3) Begin walking away from your monitor slowly until you've reached a distance where you can no longer tell if the pixels are stepping or not.
You now know what resolution your monitor would have to be to achieve "non-pixels" at all times.
I sit around 2' back from my screens and on a quick test using that exact same method, I need to step back to around 10-11' to REALLY make that line appear smooth. 8' the pixels start to blend, but it still looks lumpy. By 10' or so though like I said, it's more or less appearing as a smooth line to me.
So it's math time:
I needed to effectively shrink the pixel density of my screen by a factor of 5 (2' to 10') in order to reduce the appearance of the pixels such that a jagged line looked straight. That means in order for my screen to look that good from 2', it needs 5x more length and width...or 25x more resolution. The screen is 1920 x 1200, so basically my monitor would have to be 9,600 x 6,000 in order to appear completely flawless when tasked with displaying a black and white, aliased line.
In reality, we never really view black on white, aliased shapes. We view much lower contrast images where even if the lines were aliased, they are only blending between pixels with a 5-10% value difference.
When you consider that print media is regarded to be more or less perfect for viewing at standard distances when printed @ 300dpi, you can more or less figure that a computer screen only really NEEDS to be 300dpi as well.
A 24" monitor is roughly 20.33" x 12.7", which means the resolution is 6100 x 3810 in order to achieve 300dpi.Edited by kweechy - 3/24/12 at 6:43pm