The subpixel-AA debacle and font rendering

[KapnKrunchColorado]

I'm using an LG 32UK50T-W 32" Class 4K UHD FreeSync Monitor as my main display (connected via DisplayPort, 3840 x 2160), and a ViewSonic VX2703 27" as my secondary display (connected via HDMI, 1920 x 1080), both connected to a Radeon RX 580 8 GB graphics card.

I had these "fixes" implemented in Mojave, and upgrading to Catalina made everything horrible, especially on the ViewSonic.

Using the below "undo" command sequences, everything is now beautiful. No need to purchase an additional monitor at all.

YMMV.

Text (and everything else) on the P2415Q (which is not 220 ppi) looks fantastic in Catalina.

I will say though, while I was waiting for it to be delivered, I undid the old commands that worked on Mojave, with this combo (with a login/logout after each one):

defaults -currentHost delete -globalDomain AppleFontSmoothing

defaults write -g CGFontRenderingFontSmoothingDisabled -bool YES

...and text clarity did improve compared to how it looked right after upgrading to Catalina, it just wasn't great. I think there's an issue with the commands we all ran for Mojave, where somehow when you upgrade to Catalina it messes things up further.

 

[Herbit]

With these commands all the (remaining) sub pixel rendering is turned off and the the system only uses grey scale pixels for the smoothing. At least it is consistent, then. For low res displays I prefer sub pixel rendering though.

 

[StellarVixen]

With these commands all the (remaining) sub pixel rendering is turned off and the the system only uses grey scale pixels for the smoothing. At least it is consistent, then. For low res displays I prefer sub pixel rendering though.

Grayscale antialiasing does not do much to help with non Retina monitors.

Nothing can replace RGB subpixel antialiasing. That’s why UI fonts look hideous in Catalina on anything non Retina.

 

[theorist9]

Here's a great blog (author: Steve Gibson of Gibson Research Corp) that gives a clear, illustrative explanation of how subpixel rendering actually works. Essentially, by using the subpixels, you are (approximately) effectively tripling the horizontal resolution of the display (at the cost of some color fringing):

GRC | How Sub-Pixel Font Rendering Works

A complete and clear explanation of Microsoft's 'ClearType' Technology -- including a freeware demo application.

www.grc.com

[My comment is that it may not effectively be quite like tripling the horizontal resolution, as the subpixels may not give as sharp an edge as full pixels (some of this may be reflected in the color fringing). I.e., to human perception, a display that actually has triple the horizontal ppi may, without subpixel rendering, look sharper. Having said that, it's still clear that subpixel rendering provides a substantial boost in horizontal resolution.]

 

[StellarVixen]

One more thing, to all of you who are using HDMI connection to your monitors, try to enable 4:4:4 RGB instead of YCbCr, which is default on Mac OS when using HDMI.

Big difference, trust me.

 

[StellarVixen]

Out of curiosity, I took a look at how fonts are rendered in Snow Leopard, and it seems that it's using grayscale method.


Now this might be due to fact that I am running 10.6 in virtual machine, and graphics acceleration is not possible in VMs, but I remember when I used High Sierra in VM, it had RGB sub pixel rendering on, even without hardware acceleration.

 

[theorist9]

View attachment 874238


Out of curiosity, I took a look at how fonts are rendered in Snow Leopard, and it seems that it's using grayscale method.


Now this might be due to fact that I am running 10.6 in virtual machine, and graphics acceleration is not possible in VMs, but I remember when I used High Sierra in VM, it had RGB sub pixel rendering on, even without hardware acceleration.

It's interesting you mention Snow Leopard, because I thought that was the last OS that was good for lower-res (~100 ppi) monitors. I wasn't comfortable with font rendering post-SL until I got a 4K monitor. I.e., in my view:

~100 ppi: front rendering unacceptable after 10.6
~160 ppi (4K 27"): font rendering unacceptable after 10.13
~220 ppi (5K 27" = retina): font rendering acceptable with all OS's

Also, from what I've read, SL did have the subpixel rendering capability, since that was introduced with Quartz 2D, which was pre-SL.

 

[Kutfe]

Some changes with "-int 3" monitor Benq PD2700U (ppi 163) over MiniDP with Catalina 10.15.1

defaults write -g CGFontRenderingFontSmoothingDisabled -bool YES

 

[StellarVixen]

Some changes with "-int 3" monitor Benq PD2700U (ppi 163) over MiniDP with Catalina 10.15.1

defaults write -g CGFontRenderingFontSmoothingDisabled -bool YES

View attachment 878194
View attachment 878195

Definitely a difference.

 

[Kutfe]

Definitely a difference.

I think this is good or maybe even better? ?

 

[StellarVixen]

Dunno, I am on Mojave, and using Lucida Grande as UI font.

 

[b1narych0ice]

So I've gone back and forth with these tweaks on my old 2012 rMBP, but when my new 16" arrived and I plugged it in, the most pleasant surprise was that THE FONTS ACTUALLY LOOK GOOD -- better than with any combination of the tweaks and removals in this thread did on my old machine, while hooked up to the same monitor.

The only other explanation I can think of is that maybe whatever was wrong had to do with having an Nvidia GPU vs the AMD GPU in the new machine, and some kind of driver issue or bug? I'm happy and all that my fonts are rendering properly on the new machine, but this only confirms my feelings that the fonts just weren't quite right on my old machine.

 

[reda-alaoui]

I was on Linux PC with a Samsung C43J89 3840 x 1200 @ 120 Hz.

I received a new Macbook Pro 16, connected it to the same monitor.
Tried everything, the text looks bad :/

Going to send it back I guess ...

 

[cybercap]

Hi,
Went quickly through these interesting pages.

Would someone be kind enough to sum up what I should be using for the best rendering on:
- an iMac 27" 5K on the latest catalina version
- a Mac Mini connected to a 24" Dell standard 1920x1080 monitor on hdmi also running the latest version of Cat.

Thanks.

 

[BohdanKolesnyk]

Text (and everything else) on the P2415Q (which is not 220 ppi) looks fantastic in Catalina.

I will say though, while I was waiting for it to be delivered, I undid the old commands that worked on Mojave, with this combo (with a login/logout after each one):

defaults -currentHost delete -globalDomain AppleFontSmoothing

defaults write -g CGFontRenderingFontSmoothingDisabled -bool YES

...and text clarity did improve compared to how it looked right after upgrading to Catalina, it just wasn't great. I think there's an issue with the commands we all ran for Mojave, where somehow when you upgrade to Catalina it messes things up further.

Yes, I can confirm that if you do these commands on Mojave before the update, things might be better on Catalina. And yes, it almost looks like on Mojave then (tested on iMac late 2015 21,5”)

 

[zeiter]

Some changes with "-int 3" monitor Benq PD2700U (ppi 163) over MiniDP with Catalina 10.15.1

defaults write -g CGFontRenderingFontSmoothingDisabled -bool YES

View attachment 878194
View attachment 878195

Hi there, I have the same screen connected to mdp with catalina 10.15.2 I have done the formula in the terminal and well, i think the text is still fuzzy. I am in "look like" 1440p. What sharpness setting do you have in the display's menu?

Do you guys think a 25 inch 1440p monitor (instead of this 4k) will look good enough? 4k with a non 4k screen on windows is ugly so I might change to 1440p...

 

[Idec50]

AFAIK these settings do not improve fonts inside Web browsers. I tested with fontsmoothing off, on and set to 3. So, we are left with this:

Compared to this in Windows:

The latter is a hell of a lot more clear and easy to read from further away. How the hell is this acceptable?

Has anyone found settings that improve Web fonts?

 

[BohdanKolesnyk]

How the hell is this acceptable?

Unfortunately, macOS regression is an official Apple policy now (aka "Refinements")

 

[Ritsuka]

Subpixel antialiasing has been removed in 10.15, you can reenable it. The only solution is to buy a monitor with > 200 ppi.

 

[theorist9]

AFAIK these settings do not improve fonts inside Web browsers. I tested with fontsmoothing off, on and set to 3. So, we are left with this:

View attachment 891627

Compared to this in Windows:

View attachment 891628

The latter is a hell of a lot more clear and easy to read from further away. How the hell is this acceptable?

Has anyone found settings that improve Web fonts?

It's the nature of the difference between Windows and MacOS. Windows is designed to display readable text on the widest possible range of monitors, including those with low ppi. With MacOS, by contrast, as higher ppi displays come available, they jettison the functionality that allows text to look good on lower ppi displays. They did this once before, when they went from 10.6 to 10.7, as well as more recently, when they went from 10.13 to 10.14.

[You can bring back the subpixel antialiasing in 10.14, using Terminal commands; but because 10.14 wasn't designed to be used with this, it still can't be made to look as good (for text) as 10.13.]

I agree, it sucks for those whose displays aren't all retina, which comprises most of those that use their Macs with external monitors. That's why I'm sticking with 10.13 as long as I can.

 

[zeiter]

I guess I'll go back to windows...I have been using it a lot at work and I like it more and more...I'm just tired of OSX little things like this....and I don't have the budget to buy new macbook pro so I can support the LG 5k display...

 

[Viamusic10000]

It's the nature of the difference between Windows and MacOS. Windows is designed to display readable text on the widest possible range of monitors, including those with low ppi. With MacOS, by contrast, as higher ppi displays come available, they jettison the functionality that allows text to look good on lower ppi displays. They did this once before, when they went from 10.6 to 10.7, as well as more recently, when they went from 10.13 to 10.14.

[You can bring back the subpixel antialiasing in 10.14, using Terminal commands; but because 10.14 wasn't designed to be used with this, it still can't be made to look as good (for text) as 10.13.]

I agree, it sucks for those whose displays aren't all retina, which comprises most of those that use their Macs with external monitors. That's why I'm sticking with 10.13 as long as I can.

Text seems fine on my 27inch 4k. Why did apple nuke sub pixel AA?

 

[theorist9]

Text seems fine on my 27inch 4k.

This depends on how sensitive you are to text sharpness. I have a 27" 4k and, for me, text is noticeably sharper in High Sierra than Mojave/Catalina. That's partly due to my own prediliction for very sharp text, and partly that my close vision is pretty good: I can still (though barely) read the microprinting on a Series 2013 $20 bill. ["THE UNITED STATES OF AMERICA 20 USA 20 USA" is written in black in the border below the Treasurer’s signature.]

Why did apple nuke sub pixel AA?

From:

macOS 10.14 Mojave: The Ars Technica review

Dark Mode and iOS apps make this desert-themed release feel surprisingly verdant.

arstechnica.com

"Apple says that the removal of subpixel rendering is because the effect depends on a specific subpixel arrangement, which could be reliably assumed in the early days of LCDs but can’t be relied upon now that different technologies (like OLED) use so many different subpixel arrangements. For instance, the iPhone X’s OLED screen uses a diamond subpixel layout, a radical departure from RGB stripe subpixels.

This argument doesn’t quite pass muster, since the older non-Retina screens that MacBook Airs and iMacs are using are precisely the kinds of screens that are still using the classic RGB stripe subpixels that subpixel antialiasing was designed for. But it’s the same argument that Microsoft has used when disabling ClearType in latter-day versions of Office, so it’s not unprecedented. And Apple has tweaked some fonts over the course of the Mojave betas to improve areas of the operating system that looked especially bad without subpixel rendering."

 

[Ritsuka]

Subpixel anti-aliasied text needs to know the background on which will be rendered, because it uses coloured pixel that can't be simply composed over a different background.
It required a lot of specific code to not look horrible on macOS translucent views, and it still looked horrible in many places.

 

[frou]

Subpixel anti-aliasied text needs to know the background on which will be rendered, because it uses coloured pixel that can't be simply composed over a different background.
It required a lot of specific code to not look horrible on macOS translucent views, and it still looked horrible in many places.

Here's a quote from another site expanding on this:

ex-MacOS SWE here. Subpixel antialiasing is obnoxious to implement. It requires threading physical pixel geometry up through multiple graphics layers, geometry which is screen-dependent (think multi-monitor). It multiplies your glyph caches: glyph * subpixel offset. It requires knowing your foreground and background colors at render time, which is an unnatural requirement when you want to do GPU-accelerated compositing. There's tons of ways to fall off of the subpixel antialiased quality path, and there's weird graphical artifacts when switching from static to animated text, or the other way. What a pain!