Resolution is a term that is thrown around with reckless abandon like mashed potatoes at a food fight. Unfortunately, it’s a term that is rarely used properly.
While many people refer to resolution simply as the pixel counts in the final display image or as the number of photosites on a camera’s sensor, neither of them are actually resolutions: 1,920 × 1,080 is not resolution, it’s merely the number of pixels in an image. Likewise, the Red Epic may have 5,120 × 2,700 active photosites on its sensor, but that is not a definition of resolution, either.
Resolution is reliant upon, yet independent of, the number of photosites on a sensor and the final number of pixels within the display image.
Resolution, by definition, ...