Both iPhones and Android smartphones now have standard cameras that support the so-called HDR mode. The standard can also be found in television sets. But what is behind the term? TECHBOOK explains.
The term HDR has become a trend in the industry in recent years. TVs, cameras and smartphones can handle HDR, but the term does not always have the same meaning. While HDR on televisions is based on special hardware, the camera technology in smartphones with and without the standard is the same. The manufacturers enable HDR recordings here with the help of special software that can enable recordings with more contrast and details. But what is HDR for anyway?
What does the term mean?
HDR is the abbreviation for “High Dynamic Range”, translated as “high dynamic range”. So the technology describes the ability to perceive more than normal optics do. It was first used in the mid-1980s in the field of image processing on the computer, but a little later the technology was also found in photography. Smartphones with HDR have also been available since around 2012. The Google Nexus 4 was one of the first models to have HDR functionality built into the camera as standard. TVs use High Dynamic Range to improve the picture and present reality as authentically as possible.
How does HDR work on smartphones?
The HDR function is part of the camera software on Android smartphones and iPhones, so it is not based on the built-in hardware. Enabling the feature is easy. As a rule, the appropriate menu item for this can be found in the settings of the camera app.
Enable HDR in the smartphone camera
Android users can access the function directly via the camera, click on “Settings” and on “HDR”. They can then choose to turn on always mode or only when needed (automatically when exposure requires it).
Owners of an Apple iPhone go to the settings of their device and select the “Camera” item there. Here you will find the “HDR” area a little further down and activate “Intelligent HDR”. If you want to save a version without the mode in addition to the optimized recording, you can also check the “Keep normal photo” box.
If HDR is used when taking photos with the smartphone, the camera takes several (usually three) shots in a row in a short time – each with a different exposure value. The software then merges the captured images into a single photo. The result is images with more detail, optimal exposure and strong contrasts that are closer to what the human eye perceives than a conventional non-HDR photo.
In principle, high dynamic range is an advantage for smartphone cameras. The technology eliminates problems such as photos that are too bright or too dark, flat details and too little dynamics.
In these situations, you should use HDR
- landscape shots: Some details can be lost due to unfavorable exposure, especially in landscape shots. HDR compensates for the difference in exposure between sky and landscape and prevents certain areas from appearing overexposed.
- Whenever the sun is glaring: Strong rays of the sun wash out the colors and often also cause glare in the lens. Disturbing shadows can also appear. Users can prevent all of these points by activating High Dynamic Range on their smartphone.
Also read: The smartphones with the best camera
HDR is not always recommended for photos
However, there are also some situations in which high dynamic range tends to degrade the recording.
- Recordings with movement: Since HDR takes several photos in quick succession, blurring quickly occurs when there is movement.
- High contrast is lost: For example, if you want to photograph the silhouette of a body in the dark, HDR mode would blur the contrast.
Conclusion: Even the HDR mode cannot save a dark backdrop. When used correctly, however, your photos will become significantly more detailed.
High Dynamic Range on TV
The term HDR is also often found in TV sets. Unlike the smartphone camera, however, high dynamic range is not implemented via software here, but requires special hardware. But the standard should also provide higher-contrast and more vivid images for televisions.
The higher image contrast results from an increase in the brightness range and thus achieves a greater depth effect. The image looks more vivid because HDR recognizes more nuances of brightness and objects are better shaded. At the same time, thanks to High Dynamic Range, images are displayed with more colors. While SDR still has an image depth of 8 bits, HDR has 10 or even 12 bits. Simply by increasing to 10 bits – also known as HDR10 – the number of colors that can be displayed increases from 16.77 million to over a billion. However, whether the TV actually displays an HDR image depends on several factors.
First of all, the entire transmission path must support the standard, i.e. the screen, the player, the connection cable and the data carrier. If the path is interrupted at just one point, the final image will not be broadcast in HDR. There are also TV sets that cannot really display High Dynamic Range, even if they adorn themselves with the said logo. The logo just means that the device can read the signals. The transmission usually fails because the devices do not achieve the necessary range in terms of brightness.
Also read: The perfect TV picture with just a few settings
Differences between HDR, HDR10, HDR10+ and Dolby Vision
HDR comes in different levels and norms. The simplest variant is HLG (Hybrid Log Gamma), which does not transmit any information, but can display HDR images with the lowest quality on average 4K TVs. The standard is optimized for the limited bandwidths available to TV broadcasters.
Much better known and most widespread is HDR10, which transmits basic information once in order to mark out the lightest and darkest picture detail of the entire film. The norm is static, so one HDR setting applies to an entire movie. Individual scenes can therefore not benefit from it, and HDR10 does not transmit as many brightness nuances. HDR10 already increases the image depth significantly.
HDR10+, on the other hand, is dynamic HDR, which means that it adjusts the contrast information for each scene individually. As far as the number of nuances is concerned, it can be compared to HDR10. The standard was introduced by Samsung because they did not want to pay a license fee for HDR10 Dolby Vision and therefore developed their own solution. Samsung allows the use of HDR10+ without a license fee. HDR10+ has almost no quality differences to the aforementioned Dolby Vision (DV). Dolby Vision also works dynamically and offers a variety of nuances.