[smichel17]

What counts as hidpi?

I have 20/20 vision, and normally sit with my eyes approximately 3 feet away from my monitor (based on a rough measurement just now). My 27" 4K monitor has ~160 PPI, and I cannot discern individual pixels until my nose is around 1.25 feet away from the screen. My old 24" 1080p monitor has 92.5 PPI, and I remember being able to see individual pixels at the normal sitting distance.

Subjectively, my 4k monitor is a big upgrade; you won't hear me arguing that PPI doesn't matter. Based on my ballpark measurements, though, 138 PPI seems like plenty, as long as your monitor isn't right up in your face.

[reacharavindh]

I’m not sure of the scientific background. But, HiDPI displays on Macs have spoiled me with text rendering that is so sharp that I cannot bear to work with low(er) resolution displays anymore. I always attributed this “sharpness of text” trait to the high DPI that Apple displays tend to have. Hence my disappointment with the new LG monitor.

[smichel17]

Update: I played around with font settings, and if I disable antialiasing then I think am able to see individual pixels around the curves of letters. I say "think" because I can definitely pick out the sharp edges, but I'm not sure if I can identify the specific pixel. It becomes especially apparent (no longer a single pixel, I think) if you change the display scaling to 2x or 3x.

I'm not a font expert, and I stopped myself from going down a rabbit hole, here. So I'm not really sure if this is a fault of the monitor, the renderer, the font itself, or some other piece I'm not aware of. Are there fonts which are designed for display on ~150 PPI screens, which don't need antialiasing so much? I know MacOS doesn't do subpixel rendering, but I assume it does some form of antialiasing? Or does it use a higher DPI font as I was speculating about?

Overall, the experiment has convinced me that there is some benefit to higher PPI. I maintain that my ideal monitor would be something like a 16:9, 40 inch¹, 8k monitor. I'd run things at 2x scaling to avoid fractional scaling headaches. The increased screen size would leave the size of everything after scaling slightly smaller than on a standard 24 inch, 1080p sceen. And the 200+ PPI would keep everything looking crisp at that size (I find the extra pixels from 4k makes text legible at slightly smaller sizes).

[1]: I'm not sure that's the exact right size, I need to re-do my calculations for how large I want stuff to be at 2x scaling.

[smegsicle]

note that macos eschews the subpixel rendering strategies other major vendors use to increase sharpness and legibility at reasonable DPI

[smichel17]

I am not sure how to parse your sentence, because I don't know whether your "reasonable" means low or high. It could be

1. Other major vendors use subpixel rendering strategies to increase sharpness and legibility at reasonable DPI. MacOS eschews these strategies.

2. Other major vendors use subpixel rendering strategies. MacOS eschews these strategies to increase sharpness and legibility at reasonable DPI.

[reacharavindh]

That is sad news. I have a Linux Desktop that emits not so sharp text on my 1440p monitor. I always attributed to that bad text rendering to the low DPI monitor. I was hoping that one day I could buy a hidpi monitor that would make my Linux desktop as friendly to my eyes as my MacBook Pro. Looks like not anytime soon :-(

[smegsicle]

I meant that (imo) Windows's 'ClearType' hinting is sharp and easy to read at lower DPI-- Linux font rendering can be configured as 'hintslight' for MacOS-style blurry-but-preserving-font-shape, or 'hintfull' for MSWin-style aggressively-snap-to-grid-for-sharpness-and-legibility.

There is ofcourse more that can be misconfigured, but if you've got blurry fonts on Linux, there's a good chance changing the hintstyle to hintfull could tighten things up.