Everything in technology needs a label, ideally a three letter acronym. When you open this little box, some seemingly random words tumble out of it. High Dynamic Range, HDR, is a way to record photo and video that give you brighter colours, even in darker circumstances. In this article I will explain how HDR recording works and how colour information is stored, coded and transferred to the viewing device.
HDR technology and its history
When you capture images with HDR you actually capture multiple images. These images have different exposure times and are then put together again, with algorithms, to form a well-balanced and lighted image.
When I did research, I found out that this technology to pick out the best lighted parts out of multiple photos is not new. This technology was pioneered in the 1850s by an innovative photographer called Gustave le Gray. He went out to the beach and photographed the sea and the sky. He took multiple photographs with different exposures and then later manually added them together to a single photo again. Furthermore, he cleverly used the horizon to make the cut.
Watch HDR video
To see the monochromatic HDR from le Gray you only needed paper and your eyes. To watch HDR video on modern screens, you need to have a proper HDR source and a supporting device. And then there is the second aspect of HDR video. You not only compose an image out of multiple versions, but also describe and store more colours compared to regular video. There is also a bigger colour space (palette or gamut). The specification that describes this colour space is called Rec. 2020.
If you receive the video, make sure you have a good internet connection because more data is required for HDR. All the extra information for the more realistic colours is actually contained in every frame of video. Examples of HDR video sources are Netflix and YouTube. For Netflix, you will have to pay premium to see HDR, YouTube has demo video’s like this one:
Depending on if your device supports HDR, you can see these encodings under settings.
And of course, you can view your own video’s that are recorded and stored with HDR. Check out this article if you want to produce your own HDR content: