Hi, 

it looks like you are observing the same issue as reported here :

https://developer.vuforia.com/forum/ios/sdk-version-3-0-5-retina-resolution-problem

?

If so, could you post and follow up in that thread ?  we are currently looking into this, and we will update on this issue in that thread.

HD video background dont work on iPad4 :( Why ?

If you refer to this :

https://developer.vuforia.com/resources/dev-guide/hd-camera-view

This feature is about the ability of retrieving a Camera Frame at HD resolution (on devices that include a HD camera and screen, and quad core processors, as mentioned there).

It is not about video recording or sharing of video;  the dev guide mentions :

Apps can offer features such as recording and sharing of images and videos in HD

as an example of what your App could do by using this feature;   however, the recording and/or sharing of images and videos is not a feature of the SDK per-se,  but it is something that you would need to implement at application logic.   What the Vuforia API offers is just the ability of retrieveing a Camera Frame, as explained in these articles:

https://developer.vuforia.com/resources/dev-guide/unity-camera-image-access

https://developer.vuforia.com/forum/faq/android-how-can-i-access-camera-image

I am also very intrested in this upgrage . Any info on this would be of great help :)