Why are HDR version and UHD version files different sizes?
There are a variety of factors that determine the size of the movie downloads. One important factor is that the UHD and HDR versions of the movie have been prepared independently by the movie studio, optimized for the target viewing environment. There are some potentially significant differences between one versus the other. One significant difference can be the amount of grain in the film – accurately encoding film grain requires significantly higher bitrates, and HDR versions are often “cleaner” in this regard. This is particularly common with newer animated films. It is also important to note that while HDR10 content can represent a much wider range of brightness values and colors, it does not achieve this by using more data, but instead by representing the data better. This means that in most cases, the size of the UHD and HDR versions should be very similar despite providing different viewing experiences.
