Confusion regarding operation resolution and DPI scaling on Windows 7

[wirewick]

Hello tomshardware, for my first post here I would like to pose a question about native resolutions, operating resolutions, etc. I will try to be thorough without being overdrawn:

I had the chance to play around with a friend's 15.6" Latitude 5540 with a 1080p display. My first impression was that the display was nice however things like the icons, windows bars, chrome web browser controls, etc. all seemed to be a bit small for my eyes. We went and tried changing the operating resolution for Windows but were surprised to see that there weren't really any other resolution settings that fit the widescreen. Then, we tried changing the setting (which I believe controls the DPI scaling of the OS? It says "make text and other items smaller or larger") up to 150% from the default 125%. This produced a result similar to what I was looking for. The icons grew and everything was relatively more visible, however I noticed a bit of blurriness on some things.

So now I am left with a bit of confusion as to why this would occur. Also, I am trying to understand the effective difference between
1. Using a 1080p display at native resolution with Windows 7 "Make text larger" setting
and
2. Using say a 768p (the other screen available on this computer) at its native resolution.

I hope I was clear enough in my wording. Basically what this comes down to is a decision; 1080p or 768p on a 15.6" Windows 7 Laptop

Thanks

 

[ScrewySqrl]

basically, things will look a bit blurry because of the nature of LCD Pixels.

By default, there is one LCD cluster (a blue, green, and red LCD) for each pixel in the native resolution (in a 1920x1080 screen, thats means 1920 clusters across and 1080 down, a total of 2,073,600 clusters. At one cluster per pixel, it will be sharpest, because at a lower resolution, each 'pixel' covers one cluster and just a little bit more. so at 720p (1280x720) , for instance, each pixel takes up 1.5 of the clusters both across and down, causing a slight blur: 3 clusters for every 2 pixels.

 

[wirewick]

That makes sense. First time I've heard about three piece clusters comprising each pixel. Still I am confused about resolution settings vs windows scaling settings.
Is the windows setting for making icons bigger the same as running a resolution smaller (less pixels) than native? If that's the case then I wonder why there is the option to change both

 

[ScrewySqrl]

technically, no. The 'make text larger' just enlarges text - makes it take more pixels. Shouldn't change the size of a pixel the way changing resolution does. However, depending on how the font was made, scaling it up may introduce 'jaggies' jagged angles, which might look a bit blurry from a distance. Windows should be able to smooth that out, depending on the font itself. But if that is looking blurry to you, you probably don't need to blow the letters up that large

 

[wirewick]

Gotcha. Technically no. But fundamentally, yes? Or are there still some programs that will present themselves with smaller text?
For someone with i'm imperfect vision should l opt for the 768p or will I be OK with 1080p at 150% setting?
Thanks

 

[ScrewySqrl]

I'd suggest 1080p and 100% for the sharpest picture. 1080 and 125% or 150% otherwise

 

[wirewick]

Ok thanks. Hopefully it will be acceptable for me to bump this thread in case I come up with any further questions.
Also I found it interesting to find that the 1080p Dell was set to 125% by default.