How HDR Colour Grading Differs From Standard SDR Colour Grading

Many people have experienced switching between devices and noticing that the same video can appear noticeably different. A bright scene may look vivid on one screen and subdued on another, or colours may shift depending on each display’s capabilities. These variations are influenced not only by the screen itself but by the format used during production, which determines how brightness and colour information are stored and reproduced. Modern workflows often involve High Dynamic Range alongside the long established Standard Dynamic Range. SDR reflects older limitations, while HDR supports higher brightness levels, deeper shadows, and a wider range of colours. These characteristics affect how professionals shape an image during post production. Differences in luminance, colour range, and detail create distinct approaches to colour grading, and understanding these distinctions helps explain why HDR and SDR must be handled with separate methods to maintain consistency across viewing platforms.

Dynamic Range Mapping: Regrading for Brightness Extremes

HDR expands the possible brightness levels far beyond the limits of SDR. SDR is traditionally mastered around one hundred nits, while HDR often targets one thousand to four thousand nits, depending on the intended delivery format. These higher brightness levels do not simply translate into a brighter picture. They reveal more detail in reflective areas and in strong light sources, which means highlight control becomes a central task during colour grading.

In SDR, many bright areas compress naturally because the display cannot present fine detail in high luminance zones. HDR changes this completely. Bright elements such as sunlight, chrome reflections, and illuminated signage retain texture and variation that must be managed carefully to avoid clipping or discomfort for the viewer. Colourists therefore evaluate the peak brightness of each scene and adjust highlight roll off curves to maintain balance. This requires time and attention because variations in peak luminance influence how the scene will appear on different HDR capable displays.

Colour Volume Expansion: Working With a Larger Gamut

HDR expands the available colour volume beyond the limits of SDR. SDR colour grading relies on the Rec. 709 colour space, while HDR formats often use Rec. 2020 or DCI P3. These wider gamuts allow deeper reds, richer blues, and more saturated greens that were previously unattainable. With this increased range comes the responsibility to manage colour behaviour carefully so that the final image remains controlled and intentional.

Professionals commonly monitor several areas when working with expanded gamuts:

The stability and accuracy of hue values across the wider colour range.
The risk of excessive or unnatural saturation when grading with extended colour volume.
The fidelity of skin tones within broader gamuts, which can shift more noticeably without proper adjustment.
The behaviour of colours across different brightness levels, since luminance changes can affect perception in HDR.
The accuracy of monitoring equipment, which must be capable of representing the full colour space used during grading.

Wider gamuts offer more creative flexibility, but they also heighten the importance of precise control. Colour grading in this context aims to preserve natural balance while taking advantage of the increased palette that HDR provides.

Precision Highlight Shaping: Specular Detail Management

Reflective materials behave very differently in HDR. Surfaces like glass, water, polished metal, and even skin can show strong specular highlights that stand out more prominently due to the greater luminance headroom. In SDR these areas often compress into a uniform bright patch, which naturally softens their intensity. HDR reveals every contour within these reflective shapes.

This clarity requires careful management. Colourists often isolate highlights using luminance qualifiers, masks, or other selective techniques to soften harsh areas, reduce glare, or shape reflections. The aim is not to dull these highlights but to guide them so that they remain informative without overwhelming other elements in the scene. Advanced highlight shaping techniques are commonly applied to achieve a balanced look that aligns with the intended visual style.

Shadow Fidelity: Noise Management in Low Luminance Zones

HDR exposes far more information in dark areas than SDR, which can reveal noise that would normally be hidden. This means shadow regions require careful attention, as the extended range presents both an opportunity to preserve depth and a challenge in maintaining a clean, controlled appearance. Unintended texture or artefacts can become visible when brightness levels are expanded.

To manage shadow detail effectively, colourists often address the following:

Noise or grain that becomes visible when HDR exposes additional shadow information.
Compression artefacts that may surface due to the increased contrast range.
Micro contrast variations that can disrupt smooth gradients in low light regions.
The risk of flattening the image when shadows are lifted too much in HDR.
The need to balance clarity with the intended mood of the scene.

The objective is to retain detail without introducing distractions. Colour grading in HDR often involves delicate adjustment of shadows so that they support the wider dynamic range while remaining consistent with the visual style.

Tone Mapping Strategy: Preparing HDR Content for Multiple Deliverables

HDR production often involves delivering multiple versions of the same content. Common formats include HDR10, HDR10 Plus, HLG, and Dolby Vision, along with a separate SDR version for platforms that do not support HDR playback. Each format interprets brightness differently, so colourists must design a tone mapping strategy early in the workflow.

This planning includes selecting the mastering brightness for the project and setting values such as MaxCLL and MaxFALL, which describe how bright the content can get and how much of the frame can reach those brightness levels. Tone mapping ensures that details remain consistent across formats. Colourists often adjust contrast, saturation, and highlight behaviour differently for each version. Without this stage, the visual intent may shift when the content is viewed on displays with varying capabilities.

Metadata Driven Colour Workflows: Static and Dynamic Metadata

Metadata plays a significant role in HDR delivery. It informs compatible displays about the mastering brightness, colour volume, and other factors that influence how the image is interpreted. HDR10 depends on static metadata that applies the same information throughout the entire programme, while formats such as Dolby Vision or HDR10 Plus use dynamic metadata that can vary across scenes or frames.

The metadata process usually requires attention to several elements:

How static metadata communicates mastering display values and content brightness levels.
How dynamic metadata adapts instructions moment by moment to maintain consistency across varying scenes.
The alignment between metadata values and the colourist’s creative decisions.
Verification that metadata accurately represents the intended luminance and colour information.
The potential for display variation if metadata is not configured correctly.

Accurate metadata helps maintain the intended appearance across a wide range of HDR capable displays. It supports the colour grading decisions made during production and ensures the final output behaves predictably.

Monitoring Requirements: HDR Reference Displays for Accurate Mastering

HDR grading cannot be performed accurately on standard SDR monitors. HDR capable reference displays are required, with the ability to reach high brightness levels, present deep blacks, and reproduce wide gamuts. These displays must be calibrated regularly to maintain colour accuracy and brightness consistency.

Professional reference monitors can display fine highlight detail and subtle differences in shadow regions that consumer devices might interpret differently. This means HDR grading must take place in a controlled environment with appropriate lighting and viewing conditions. Reliable monitoring is fundamental to producing a grade that behaves predictably across various HDR capable displays while preserving the creative intent.

Exposure Interpretation: Rebalancing Camera Log Footage for HDR

Most modern productions capture images in Log or RAW formats because these formats store a wide dynamic range. When colour grading for SDR, Log footage is compressed into a narrower tonal range. HDR allows more of the original camera information to be used, which often requires rethinking how exposure should be interpreted.

Midtones might shift to take advantage of HDR luminance levels, and highlight preservation becomes more important because HDR maintains detail in bright areas that SDR would compress. Colourists often revisit the camera intent to ensure that the HDR grade reflects how the scene was originally captured while making full use of the sensor’s latitude. This process strengthens the connection between production and post production because exposure decisions carry greater influence in HDR.

Creative Intent Re-Evaluation: HDR Alters the Visual Language

Certain looks that function well in SDR do not translate directly into HDR. Very soft highlights can appear flat, while matte or low contrast styles may lose definition on HDR displays. Conversely, HDR can emphasise elements that may not have been intended to stand out. Professionals review the creative direction during grading to ensure that the final image aligns with the intended style.

Adjustments may include refining contrast distribution, moderating saturation, or reshaping highlight and shadow relationships. HDR encourages a re-evaluation of stylistic decisions to ensure that the expanded range enhances the intent rather than creating inconsistencies. This stage often becomes a thorough exploration of how light and colour behave across different tonal areas.

Deliverable Validation: HDR Compliance, Legal Levels and Quality Assessment

HDR deliverables require a thorough validation process. The expanded brightness and colour range introduces conditions that are not part of standard SDR assessment. Checks must confirm that the content meets technical requirements for both luminance and colour, and that it responds consistently across different HDR formats and displays.

Colourists and quality control specialists often verify:

Peak luminance levels to confirm they align with the selected mastering format.
That the colour signal remains within the intended gamut without exceeding boundaries.
Metadata accuracy for formats such as HDR10, HDR10 Plus, HLG, or Dolby Vision.
That transitions between scenes maintain consistent brightness and colour behaviour.
The stability of the grade when viewed on a range of HDR capable devices during testing.

These assessments help ensure that HDR content remains faithful to the intended grade and performs reliably across platforms. The broader requirements of HDR make validation an important final stage in the colour grading and delivery process.

A Broader Perspective on HDR and SDR Variation

Understanding the difference between HDR and SDR provides insight into why modern productions treat these formats as distinct rather than interchangeable. HDR expands brightness, colour range, and detail in ways that require dedicated workflows, specialised monitoring equipment, and careful decision making. Colour grading plays a central role in shaping how these extended ranges behave. Each section of the workflow, from highlight control to metadata validation, contributes to the final presentation.

The move toward HDR capable displays has changed how visual content is produced, checked, and delivered. SDR remains widely used, but HDR introduces opportunities to achieve a more precise and nuanced presentation when managed correctly. These differences reveal why HDR grading is treated as a specialised process supported by clear technical and creative practices.

Colour grading shapes the final presentation of every production and influences how each scene is read. At Sound Idea Digital, we approach this stage with accuracy and intention. Contact us to discuss the grading requirements of your next project.

We are a full-service Content Production Agency located in Pretoria, Johannesburg, and Cape Town, South Africa, specialising in Video Production, Animation, eLearning Content Development, and Learning Management Systems. Contact us for a quote. | enquiries@soundidea.co.za | https://www.soundideavideoproduction.co.za| +27 82 491 5824 |