[yodsanklai]

Stupid question, but why the point resolution for the iphone 6+ isn't a perfect divider of the pixel resolutions like it is for the other iphones?

Since there is more than one point resolution anyway.

And also, how is it different for android devices?

[MCRed]

Not a stupid question as you've hit on the major strategic bit of news here that most people, I think, are missing.

Displays are cut from larger pieces of display material at a given PPI. So Apple focused on perfecting a 163PPI display material and then tended to use it on multiple products. They'd do the same thing for the retina display material as well (I think at one point the iPhone and iPad used the same display material and it was just cut to different sizes in making the display)

Apple could do this because they work so closely with their display manufacturers and they care so much about fidelity. It just happened that doing rigid multiples of the original display size was convenient for software as well.

However, displays have become more commoditized, especially retina resolution ones (at the time it was introduced, Apple was the only one shipping these kinds of displays in such volume) and Apple's volume has only increased over the years.

So we're seeing a shift to more commodity display production, I believe, because the commodity market has caught up with Apple's standards. Beyond 300 pixels per inch there isn't much advantage to higher density.

But there is a huge advantage to unit volumes of a display also used in portable TVs or whatever.

The software cost of downscaling isn't significant at this point so it is an economic change.

[bzbarsky]

That explains the pixel size, but not the point size. Why not make the logical resolution 360x640 with perfect 3x upscale?

My best guess is because this would then be smaller than the iphone 6 size (in points) at a larger physical size so everything would look "too big"...

[sirn]

Doing a 360x640 will indeed create a rather awkward situation where iPhone 6 plus have less usable screen space than the iPhone 6 (which is 375x667). Though, my guess is that they want to keep the physical height of elements to be roughly the same across all iPhone family.

This way, all existing buttons that were designed with 44px tapable height in mind or any existing text could have more details in it while not appear larger or smaller than any other iPhones and will have more space to display content. I believe non-mini iPad is the only product in the iOS family that recommended 44px is physically larger than the rest.

[femto113]

I believe this is because Apple wants the logical size to correspond (roughly) with physical size. This is particularly important for user interfaces. A button needs to be sized for the human finger that is tapping it and thus should be the same physical size on each device, which in turn means it should take up a smaller percentage of the logical size of the bigger devices. The only case I know of where they broke this was the iPad mini, which has the same logical size as the larger iPad, and you may notice that everything on the iPad mini is just smaller.

[sirn]

To be fair, iPad Mini has the same PPI as the original iPhone (163 PPI) and iPad Mini Retina has the same PPI as the Retina iPhone (326 PPI) so it could be argued that iPad is the only device where everything appears larger than the rest.

[joezydeco]

Do you actually believe that LCD manufacturers screen TFT transistors onto massive pieces of glass (like TV-sized) and then slice them down to phone-sized pieces for assembly?

[femto113]

It's not quite that simple, but essentially "yes". https://www.youtube.com/watch?v=TDoxReEkHe8

[joezydeco]

In that video, the larger parent substrate glass is still partitioned into smaller segments for lithography and processing.

I was referring more to the concept that the entire substrate is built as a huge 163 dpi display and then it's a matter of customer preference how the glass is cut.

[ZeroGravitas]

There were rumours of display manufacturing problems holding up the "bigger" iPhone 6. So I wouldn't be surprised to see a minor bump up to an actual 3x pixel size in the next revision.

(This would also give them back a minor marketing advantage that they had briefly when they introduced Retina, as I'd guess most mainstream Android's will stick at 1080p)

[dcarmo]

Not stupid at all, I still don't understand the reasoning behind it.