Devices in Device Specific image set in asset catalog

Question

I want to update my app for the new iPhone 6 and iPhone 6 Plus. To do so I selected an image set from my asset catalog in Xcode 6. As I develop only for iPhone I selected "Device Specific" in the Xcode Attribute Inspector. Now I can chose between the following devices:

• iPhone
• Retina 4-inch
• iPad
• Mac

Selecting only iPhone I get these sizes:

• 1x
• 2x
• 3x

Selecting only Retina 4-inch gives me only one size:

• Retina 4 2x

Why is the 4-inch screen different from 3.5, 4.7 and 5.5 inches? It would make sense in my view to combine 1x and 2x as they are both available on devices with a 4:3 aspect ratio and Retina 4 2x and 3x for devices with a 16:9 aspect ratio.

My real question: What do I need to provide in order to support iOS 7.0 and later? I obviously don't need a 1x image as my app does not support any non-retina devices. 2x seems reasonable for the iPhone 4s. Do I need Retina 4 2x if I provide 2x already? Will the iPhone 6 use the 2x or the Retina 2x? 3x is for the iPhone 6 Plus, no question about that.

Thanks for your help.

Allusive

Answer 1

• 1x: no need
• 2x: 3.5', 4' and 4.7' — see below for 4'
• 3x: 5.5'
• Retina 4 2x: 4' if image ratio is different from 3.5', i.e. image have the same width but different height

Heterolecithal

Any idea why is the iPhone 6 using the 2x images, which are with different aspect ration (4:3 compared to the 16:9 for the iPhone 6), instead of the Retina 4 ones which are with 16:9? – Moya

I guess this page can answer your question: paintcodeapp.com/news/ultimate-guide-to-iphone-resolutions – Heterolecithal

Why there is no need for 1x? How do we design it in xib without 1x images? – Bricklayer

There is no need for 1x because only retina iPhones are able to run iOS 7 – Heterolecithal

you forgot the iPad 2. Yes, you need 1x for iOS 7. – Splashboard

That's right, iPad 2 or iPad mini for example need 1x. I did not mention them because I thought of iPhone only. – Heterolecithal