Half resolution on Iphone 5c

Why my game has a half-resolution (568 x320) on ipohne 5c. Can I change it somewhere? I noticed something similar on Samsung tablet 12.2 pro (android).
but on the Samsung Galaxy 2 Galaxy 3 I have the full resolution. What does it depend?
I have only one device ios and I can not compare this with other iPhone.

Im sorry for my engish. I hope that you understood me well;)

ps

U 4.6.1 verion deploy from PC

The settings should be in your project “Config” directory inside the “DefaultDeviceProfiles.ini” file. It should have “DeviceProfile” entries for all the different iOS devices as well as Low/Mid/High for Android devices. Each one has a scale factor set up already which you can change, and you can also add entries for other rendering features there. There are a couple examples on the Setting Device Profiles documentation page.