The late 2014 5K iMac offers an incredible 5K resolution display: 5120 X 2880, which is 14.7 megapixels, or nearly the entire resolution of many of today’s popular APS-C digital cameras.
This compares to still-emerging 4K UltraHD diplays which are typically 3840 X 2160 = 8.3 million pixels, and to HD (BluRay) which is a paltry 1920 X 1080 2.07 million pixels. Kinda funny how “HD” is now “low resolution”.
A 4K UltraHD image at 3840 X 2560 image will easily fit onto an iMac 5K display. The 8.3 million pixels will leave another 6.4 million pixels unused! Click for larger.