Panic spots an issue : the Lightning adapter to HDMI has quality concerns. Indeed, the adapter does not send a raw image on the screen, and the output is limited to 1600 x 900 instead of 1080p (with an upscale, for instance).
Opening the adapter, they discovered a SoC ARM with memory and suspect that Lightning devices send a compressed signal which is then managed by this chip. I can not really check it, but I can check the quality. And the least we can say is that it’s pretty ugly.
I used an iPhone 5 (Lightning) with a Lightning to HDMI and an iPad 3 (Dock) with a Dock to HDMI. For your own information, the second is 10 $ less than the first …
Then I got the test patterns, the two devices connected to a data acquisition card (UltraStudio Recorder) and I made the catch. Everything was done in 720p, my capture card does not allow 1080p60 necessary for Apple devices.
And it is frankly very ugly. There is a degradation (very) visible on the image.
On the text
The scale difference is essentially due to the overscan at the time of capture, but even so, it is frankly visible.
Compression is very visible on the iPhone with Lightning.
On the waves
It’s even worse here, the image is (really) ugly on the iPhone, you lose all the details.
I have other examples, with downscaled 1080p , but the first two are enough in my opinion: the picture is really bad.