Whereas the FHD configuration carries the panel name Sharp LQ134N1, our 4K UHD panel is called the Sharp LQ134R1. Dell advertises a brightness of 500 nits and a contrast ratio of 1500:1 and our independent measurements can certainly confirm the latter at 1479:1. Unfortunately, we’re only able to record a brightness of 414 nits even when set to the maximum brightness setting with both adaptive brightness turned off and Intel Display Power Savings disabled. The 4K UHD panel is dimmer than on both our FHD test units where we were able to measure 600 nits each.

Nonetheless, there are a couple of noteworthy advantages over the FHD panel other than resolution. Firstly, the 4K panel does not suffer from pulse-width modulation at any brightness level which suggests that Dell is using a different LED backlight for its 4K SKUs. The fact that there is a brightness difference between the FHD and 4K SKUs supports our speculation. Secondly, black-white and gray-gray response times are a bit faster on the 4K panel meaning ghosting is not as severe. The opposite is usually true between FHD and 4K panels and so this is an unexpected advantage.