Let me take you back to the old iPhone 2G, 3G and 3Gs. This device had a screen resolution of 320 pixels wide by 480 pixels high.
Developers were explicitly told to code for that resolution and did so with great success. This immediately raised a concern for me, what would happen in the future, when Apple would release a new device with a higher resolution, something they surely would?
Well along with many other iPhone fans we heard the keynote from Steve Jobs announcing the Retina display for the iPhone 4. This had a resolution of 640×960. It left a number of people, developers, etc wondering how they would support both the existing iPhone and the new iPhone 4 in their apps.
As I wrote in a previous post, Apple actually pulled off something very remarkable and very clever with the Retina Display. They kept the screen ratio exactly the same, and made the screen exactly twice as big.
Assets in iPhone applications not ‘Retina Compatible’ simply had all of their graphical assets doubled up in size. 320 pixels wide became 320 points wide and so on.
How did a developer support the retina display, why they simply added an image of the same ratio, but exactly doubled to their app bundle but instead of a .png extension they added @2x.png to the end of the file with the same name.
It was incredibly simple to implement and required zero code changes whatsoever.
The iPad has a resolution of 1024×768 which does look amazing but unfortunately for the iPad, the iPhone 4′s Retina Display was released only slightly after the iPad.
Now there has been lots of commentary as to what the resolution would be on the iPad 2, would they simply increase it slightly or would they change the ratio, etc. There are commentators stating that a resolution of 2058×1536 would be very unlikely due to memory requirements.
In my personal opinion, it’s actually incredibly unlikely we will see any other resolution other than either keeping the status quo of 1024×768 or going for 2058×1536.
If Apple were to release an iPad with a different screen ratio or not @2x, existing iPad apps would not fit the screen properly.
People will argue but Windows and OS X apps don’t worry about this, no they don’t but then they also weren’t explicity told your only option is to provide a full screen application like iOS developers are.
Apple could scale these, but from experience of using iPhone applications on the iPad, scaling tends to look terrible.
The reason I believe 2058×1536 is likely, is first it has been found in the iOS 4.3 beta’s a number of iBook image assets with the @2x extension and are exactly doubled, but also that Apple can apply exactly the same logic as they did for the iPhone 4 and developers will have an option to support the new display or not without adversely affecting the layout of their App.
Additionally if we don’t have a double resolution we end up with the exact same type of fragmentation of iOS that Apple complains about the Android ecosystem.
Could it be called ‘Retina’ as the pixel density probably isn’t high enough, well I don’t know.
* Image credit Glenn Fleishman