[sgerenser]

What you are describing is essentially what MacOS does. E.g. on a Retina display with a 2880x1800 screen, Apple used to render “2x” assets to a 2880x1800 buffer, so that it has the same amount of space as a 1x 1440x900 screen. If you want more space (which is now the default), it renders using 2x assets to a 3400x2000 or 3840x2400 buffer (these numbers are approximate), then scales it down to 2880x1800. So it’s never scaling anything up, only down. Of course it’s still not as sharp as rendering at the native resolution. Using 3x assets wouldn’t help unless the actual resolution of the screen was higher.

[crazygringo]

Do you have a source for that?

Because I'd love if that were true, but every explanation I've seen contradicts that.

The default isn't more space, as you write -- it's actually less space, for bigger elements. Which is why you would need to render at more than 2x. It does, indeed, scale up -- there are plenty of articles from when Retina's scaling options came out that state it does lead to a slight amount of blurriness because of this.

To be clear, under Display > Scaled, the "More Space" option is true 2x retina, while "Default" through "Larger Text" are the ones that upscale.

You can actually verify this yourself -- it you take a screenshot of any UX element at "More Space", and then take a screenshot of the same element at "Larger Text", they're pixel-for-pixel identical. For everything less than "More space", MacOS is scaling up.

[sgerenser]

What? The default is most definitely "more space" as of a couple versions of MacOS ago (or maybe it was based on the product, e.g. when they came out with a new version of the MacBook Pro in 2016 or so). I know on my 2018 MacBook Pro 13" the default was one notch over on the "More Space" side vs. exact 2x Retina. And that only makes sense, as running as if you only have the space of a 1280x800 1x screen would make me go nuts, you can hardly fit anything on the screen. I think that's what drove Apple to change the defaults from the exact 2x Retina, despite the minor loss in quality from having to render at the larger size and scale down. On iMacs which have bigger screens (I'm typing this now on a 5K iMac) exact 2x Retina is the default.

You are correct that if you go down to the "bigger text" side of things that it does scale things up, and for those sizes using 3x would give a sharper image. I hadn't even considered that though because I think most people think either the exact 2x retina resolution is fine, or if anything they want more space. The only people who would use the "bigger text" option are probably people with poor eyesight in which case it doesn't matter if its slightly more blurry.

EDIT: see screenshot here: http://imgbox.com/uxcHERt3 Default for MacBook Pro 13" is "Looks like 1440x900" which requires rendering at a resolution of 2880x1800, which is then scaled DOWN to the native resolution of 2560x1600.

[crazygringo]

We're in agreement on how it works technically:

> I know on my 2018 MacBook Pro 13" the default was one notch over on the "More Space" side vs. exact 2x Retina

That's what I meant -- it's less space (one notch over, the one labeled "Default") compared to exact 2x which is labeled the "More Space" option.

> The only people who would use the "bigger text" option are probably people with poor eyesight in which case it doesn't matter if its slightly more blurry.

I guess that's where we disagree -- my eyesight is great but I like the text on my screen to be comparable with the size of body text in books, not the size of footnotes. I like a comfortable amount of text information on screen, not crammed. And the fact this is the default option makes it seem that Apple agrees.

And that's precisely why I wish it didn't add the bluriness from the upscaling, why 3x internal would be valuable.

[sgerenser]

No, the one labeled default is one notch higher on the more space continuum than exact 2x Retina (at least on the 13 and 15” MacBook pros). On other machines, like my iMac, the default notch is exactly 2x Retina. Check out my screenshot and do the math yourself. “Looks like 1440x900” is the default notch, which means rendering at 2880x1800, which is higher resolution than the MacBook Pro 13’s 2560x1600 screen.

[crazygringo]

I stand corrected, thank you.

There were a bunch of articles way back when the scaling options were introduced that claimed anything less than "maximum space" introduced blurriness... but they were obviously wrong.

I just did the math and double-checked with screenshots, and indeed — on my 13" MacBook Pro the default is higher than 2x, not lower. It's only at the leftmost "larger text" that blurriness is introduced.

Thanks so much for the info, and I'm happy to know I am getting maximum clarity out of my Mac after all! Always good to get my misinformation corrected.

And so, never mind about the whole 3x thing... you're right, unless you need text extremely large. Cheers!