To decide which is the best HDR format, we need to know about tone mapping, color bit depth and metadata.
We will focus on metadata in this article. I have discussed tone mapping and color bit depth in separate articles.
Let’s begin.
What is metadata?
In some of the HDR-labeled TVs, you will see that the brightness of the screen remains constant throughout the movie.
The night scene appears slightly greyish instead of pure black. The day scene or the lights don’t appear bright enough.
This is mainly because of two reasons.
Either these TVs have a low contrast ratio and a low peak brightness.
Or, these TVs support only HDR10 format which relies on static metadata processing.
When an HDR source delivers the HDR content to a TV, it sends a set of instructions to the TV along with the content.
These instructions known as metadata, tell the TV how to display the HDR content.
The metadata is of two types: static metadata and dynamic metadata. Let’s understand them in detail.
Static vs dynamic metadata
Dynamic metadata adjusts the brightness and colors on a scene-by-scene basis.
This helps the TV to display accurate colors at the correct brightness levels to make the image appear lifelike.
Advanced HDR formats like HDR10+ and Dolby Vision use dynamic metadata processing.
Some TVs support HDR10+ while some support Dolby Vision. A few TVs support both formats.
However, it must be kept in mind that, to display HDR content accurately, the TV needs to have high peak brightness and high contrast.
On the other hand, static metadata keeps the brightness the same throughout the movie.
Therefore, you won’t be able to differentiate between an evening and a night scene or between a morning and an afternoon scene that clearly.
Having understood the basic difference between static and dynamic metadata, let’s discuss the types of HDR formats in detail.
What is the best HDR format?
Based on the type of metadata processing, color bit depth, tone mapping and maximum peak brightness, we can categorize all the HDR formats.
HDR10
- Uses static metadata
- Mastered from 400 to 4000 nits of brightness
- License-free
- Supports up to 10-bit color depth compared to SDR which supports just 8-bit color depth
HDR10 Plus
- Uses dynamic metadata
- Mastered from 1000 to 4000 nits of brightness
- License-free
- Adds dynamic metadata to HDR10
Dolby Vision
- Uses dynamic metadata
- Mastered from 1000 to 4000 nits of brightness
- License is required
- Perhaps the most advanced HDR format
HLG
- Used for live broadcast
- Combines HDR and SDR into one signal
HDR10
HDR10 is the most widely used HDR format as almost every TV supports it. It uses static metadata processing which displays the same brightness and tone mapping for the entire movie.
Thus, the bright areas may not appear as bright as they are. Similarly, the night scenes are also not that dark.
It is, of course, better than SDR but perhaps not as good as HDR10+ or Dolby Vision.
The content availability for HDR10 is tremendous. Almost every HDR content has HDR10 as the base layer or static layer upon which dynamic formats build up.
HDR10 Plus
HDR10 Plus adds dynamic metadata to the conventional HDR10 format. Thus, it adjusts the brightness on a scene-by-scene basis, as opposed to HDR10, which displays the same brightness for the whole movie.
Thus, with HDR10 Plus, the bright colors appear as bright as they should be in real life. The contrast and tone mapping is done on a per-scene or even per-image basis.
As there is a distinct separation between the bright and dark areas of the image, the picture becomes more lively and appealing to the viewers.
HDR10 Plus is an HDR format that uses dynamic metadata as well as is royalty-free. This means that if you buy a TV with HDR10 Plus format built-in, you don’t need to pay any licensing fee for its use.
Moreover, there is a lot of HDR10 Plus content available today. Thus, you can browse any HDR movie or show seamlessly on your TV.
What if my TV doesn’t support HDR10 Plus?
Suppose your TV doesn’t support this format, and you play the HDR10 Plus content on it. Then, the HDR10 version of the content is displayed on the screen, which will be of course, better than SDR.
However, a TV having HDR10 Plus support will elevate the experience to the next level with far more vibrant and punchy colors.
Dolby Vision
This is perhaps the best HDR format out there. It can support up to 12-bit color depth and can be mastered with up to 10,000 nits of brightness, theoretically.
But, practically, most of the best TVs are limited only to up to a 10-bit color depth and 2000 nits of peak brightness.
Moreover, the mid-range and the budget TVs are generally limited up to 1000 nits and 500 nits of peak brightness, respectively. Even the brightest TVs peak at 3000 nits.
Thus, content creators generally avoid mastering HDR content above 2000 nits and at 12-bit color depth.
They generally do it at 1000 nits and up to 10-bit color depth, as most of the good HDR TVs come with that much peak brightness and color bit depth.
As the Dolby Vision format uses dynamic metadata, the content is optimized on a frame-by-frame basis and is displayed with much better contrast, brightness and color accuracy.
This allows for displaying a more vivid and realistic picture quality very close to what the content creators intended to deliver.
What if my TV doesn’t support Dolby Vision?
Just like HDR10 Plus builds upon the HDR10 base format, Dolby Vision may also build upon either HDR10 or some other base format.
In case your TV doesn’t support Dolby Vision but you are streaming Dolby Vision content, then you will be able to view the HDR10 format of the content only if that content has been built upon the base HDR10 format. Otherwise, the SDR version of the content will be displayed.
HLG
HLG stands for Hybrid Log Gamma. This HDR format is compatible with both new HDR TVs as well as the old SDR TVs.
Therefore, it is preferred by broadcasters as it can live telecast on all types of TVs.
Being an HDR format, it is certainly better than SDR, like HDR10. But, it is not at par with the dynamic HDR formats, i.e., Dolby Vision and HDR10 Plus.
Comparison of various HDR formats
| SDR | HDR10 | HDR10+ | Dolby Vision | |
| Metadata | Static | Static | Dynamic | Dynamic |
| Bit depth | 8-bit | 10-bit | 12-bit (theoretical)10-bit (practical) | 12-bit (theoretical)10-bit (practical) |
| Mastering brightness | 100 nits | 400 nits to 4000 nits | 1000 nits to 4000 nits | 1000 nits to 4000 nits |
| Maximum possible peak brightness | 10,000 nits | 10,000 nits | 10,000 nits | |
| Content Availability | Excellent | Excellent | Very good | Very good |
Which HDR TV to buy?
Almost all the new HDR-labeled TVs support HDR10 as well as one of the two dynamic HDR formats, i.e., either Dolby Vision or HDR10 Plus. Some of the TVs support all three.
But, if a TV supports more HDR formats or perhaps a better HDR format, this doesn’t necessarily mean that it will display better picture quality than a TV that supports a lesser number of formats.
It all comes down to the TV’s overall performance which heavily depends on the contrast ratio of the TV as well as the maximum peak brightness it can achieve.
You can still have pure blacks with even SDR content on a TV with a high contrast ratio and a high peak brightness. This is because contrast and brightness are the native features of a TV.
Those TVs having high peak brightness and high contrast ratio come at a premium price and even the SDR content is impressive to watch on them.
Conversely, a cheap TV having poor contrast and low peak brightness claimed to have the support of even the best HDR formats would not have a good HDR performance.
Thus, if you want to experience true HDR, first of all, be willing to pay a premium price for a TV with high contrast and brightness, such as an OLED TV with good peak brightness or a highly bright QLED TV with good local dimming.
Next, decide which type of content you watch more frequently. Samsung TVs generally support HDR10 Plus and not Dolby Vision. While, LG and Sony generally support Dolby Vision and not HDR10 Plus.
A few brands like Hisense, TCL, Xiaomi and Panasonic support both the dynamic HDR formats.
Note: Always remember, the HDR performance of a TV is all about the overall capabilities of a TV as well as the HDR content it is displaying, not just the number of HDR formats it supports. I have described this in a separate article on how HDR works on a TV.
FAQs
Here are some frequently asked questions about which is the best HDR format.
1. Does a TV supporting three HDR formats have better HDR performance than another that supports only two?
Not necessarily.
The HDR performance of a TV mainly depends on the peak brightness and contrast of the TV as well as the HDR content itself, and not merely on just the number of HDR formats it supports.
2. Which of the HDR formats use dynamic metadata?
HDR10+ and Dolby Vision. They optimize the content on a frame-by-frame basis.
3. How many colors are possible to show on display with a 10 color bit-depth?
Number of possible colors= 2^10 * 2^10 * 2^10= 1.07 billions.
4. Can Dolby Vision show you content with 10,000 nits of peak brightness?
It is not practical because 10,000 nits of brightness is beyond the range of the available displays. However, it may be possible in the future.
