What exactly is the difference between the TB Display and the Retina screen?

Discussion in 'Mac Accessories' started by theuserjohnny, Oct 24, 2012.

  1. theuserjohnny macrumors 6502

    Jul 7, 2012
    So I know both the retina screen and the TB screen both have high resolutions?

    So what's the difference?

    My understanding of retina is that it's just doubling the pixels so for every pixel there (say) 4 pixels. So by doing this, this helps not make everything looks so tiny on the 15inch screen.

    So if there was no pixel rendering (upscaling or whatever you call it) and you just ran the rMBP at the native resolution that native resolution is the same as the TB display's right?

    The only difference is that the TB display dosen't have the scaling because it can fit the native amount of pixels without it having to be all tiny like the 15 inch screen.

    So is scaling just a software thing? And if it is, couldn't (if we wanted to) tell the TB display to scale (where as in the rMBP it's the opposite and we can make it run native res).

    Sorry if confusing!
  2. Arline macrumors regular


    Jun 10, 2010
    Retina means that at the normal viewing distances, the pixel density is so high that your eyes can't distinguish between pixels. the TB display doesn't quality as a retina.

    Yes scaling is just a software thing. You can run the TB display at 200% DPI scaling in the same way that retina displays do which leaves you at a 1280x720 effective resolution with sharper (and of course bigger!) text or you can run a retina display (say on 15-inch rMBP) and run it at 100% DPI scaling which gives you full 2880x1800, it's just a specification difference.

    I imagine a 27-inch retina TB display (or a retina iMac) will have a resolution of 5120x2880 with 200% DPI scaling so the effective workspace will still be the same as it is now, just better.
  3. drambuie macrumors 6502a

    Feb 16, 2010
    With the TBD it's all relative. For me a TBD would effectively be retina because in my normal sitting position, my eyes are about 36" from the monitor, so the pixel size would be similar to that of a retina iPad at 18". For someone who sits very close to the monitor the pixels would be visible, but retina iPad pixels would also be visible if you hold it 4" from your eyes. The iPhone would probably be the truest retina, unless you hold it almost touching your eyeballs.
  4. MCAsan macrumors 601


    Jul 9, 2012
    Apple has not stated the Retina resolution for a 21" or 27" monitor. We only have the Retina designation on two laptops, iPads, and iPhones. The new 27" iMAc screen stays 2550x1400 and does not have Retina status. Very likely the refreshed thunderbolt display would be the same.

    For a 27" IPS monitor 2560x1400 is current state of the art. If you want 2560x1600 (max Retina screen count), you have to purchase a 30" monitor.
  5. theuserjohnny thread starter macrumors 6502

    Jul 7, 2012
    So if I scale the TB display wouldn't it just end up looking like the Retina screen on the rMBP?

    I mean both of the displays are IPS right? (PSL if you have the Samsung but it's the same thing)

    The only difference is that the Retina Macbook Pro screen's are scaled and the TB are not.

    Because if I run the rMBP screen at native resolution it would look the same as a thunderbolt (everything would look tiny as hell) but still they're the same.

    The only reason why the rMBP looks "crisper/clearer" than the TB is because of the scaling right? I mean you said the scaling gives it that "sharper" look. So if I scale the TB display I technically have retina as well.
  6. RMo macrumors 65816


    Aug 7, 2007
    Iowa, USA
    I'm not sure that you understand. In a Retina display, the pixels are basically four times denser than in a pre-Retina display (twice as many both horizontally and vertically, or at least that's the magic ratio they've been using so far). Ordinarily, this would give you twice the space but also make everything look twice as small. Because this is not what most people want, Apple instead by default doubles the DPI (so it's really running at the full, double resolution, but displays things at the same size as it would if it were running at half the resolution like a comparable non-retina display of the same size.) Let's say you had a letter "B" before that took a 16x16 pixel square to display. You had 256 dots to work with. Now, you have 32x32 pixels and so 1024 dots, but it's in the same amount of space (i.e., same number of square inches), so it will look smoother because, supposedly, at this density the eye can no longer perceive individual pixels.

    Text scales well in this way because most fonts are defined with vectors rather than bitmaps. For images, applications must provide Retina-compatible versions (i.e., twice the resolution), but if not, OS X will simply scale up the regular-DPI version. This means it will effectively look the same as it would on a non-retina display (assuming you have the default DPI doubling).

    If you half the resolution on your Thunderbolt display (I assume this what you mean by "scaling"), you will have half as much space horizontally and vertically, and everything will be twice as big. This will, in fact, take you farther away from the retina experience in that your pixels just got bigger and blockier (if not blurrier, as often happens if you don't run at an LCD's native resolution, though at exactly half of it I don't see why that would happen). What you'd have to do is double the resolution, but you can't because you don't actually have that many pixels to work with (you can't do more than your native resolution, the number of pixels the LCD actually has). Actually, you could keep your current resolution and enable "Hi-DPI" (retina) mode with Quartz Debugger or something, if I recall, but since that will make everything twice as big, I'm not sure you'd want to, and you still wouldn't get quite Retina smoothness since you are still constrained to the existing pixel density.

    Basically, Retina allows Apple to double the resolution of their displays while, by default, automatically adjusting DPI (in OS X) so most people won't notice anything but sharper text and images (if the application has provided them, otherwise a seamless fallback to regular images). It's a pretty good solution that most users don't even have to think about.

    If you're confused, I really wouldn't worry about it. You might notice sharper text and images, but it's not like anything Apple has on the market right now (including the TB display) is horrible by any means. This "regular" density has been standard for a while and it's what most people are used to and don't really care about. (I do have to say, however, I enjoy the retina screen on the iPod touch, probably because when everything is small, it enables better reading.)
  7. theuserjohnny thread starter macrumors 6502

    Jul 7, 2012
    No, this makes complete sense now! :)

    Thanks for taking the time to explain it!

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