DaVinci Resolve 21 · Resolve FX Color · NVIDIA RTX

NVIDIA RTX Video HDR

AI-assisted SDR→HDR mapping inside Resolve with explicit input/output colour-state controls, middle-gray placement, target peak luminance and creative contrast/saturation shaping.

Blackmagic lists NVIDIA RTX Video HDR as a Studio desktop Resolve FX that requires Windows, a supported NVIDIA RTX GPU and driver. Treat the hardware requirement as part of the workflow, not an optional performance hint.

Read the controls Resolve FX

Signal contract

The four dropdowns matter more than the creative sliders

RTX Video HDR is not safe to treat as a black-box ‘HDR button’. The OFX must know what the incoming RGB values mean and what representation it should produce after the AI mapping.

How to interpret the input gamut

Input Color Space

Input Color Space tells RTX Video HDR which primaries / gamut describe the RGB values at the exact OFX input. The list includes ACES AP0/AP1, Adobe RGB, Apple Log 2, ARRI Wide Gamut 3/4, Blackmagic Design gamuts and more. Use timeline is safe only when the timeline colour space truly matches the signal state at this node.

It describes input state, not a desired look
After CST/DCTL/LUT, Use timeline can become wrong
A wrong gamut invalidates the SDR→HDR mapping

Input transfer function / encoding

Input Gamma

Input Gamma defines how the input code values relate to luminance or scene encoding: ACEScc, ACEScct, Apple Log, HLG, ARRI LogC3/LogC4, Blackmagic Design Film and other options. It is not a decorative preset. If the OFX interprets log as display-referred SDR or vice versa, Middle Gray, contrast and highlight expansion operate in the wrong domain.

Treat Colour Space and Gamma as a pair
Use timeline only when node state genuinely matches
Audit source tags and upstream transforms

Target gamut after AI mapping

Output Color Space

Output Color Space defines the gamut in which RTX Video HDR should present its result. It must match the next pipeline stage and the intended HDR delivery rather than simply being the widest available option. If another output transform follows the OFX, that transform must expect the gamut selected here.

Target gamut should be part of a documented pipeline
Do not accidentally add a second gamut transform downstream
Check saturated highlights and neon after expansion

Target transfer function

Output Gamma

Output Gamma defines the encoding of the RTX-mapped result. In a real HDR workflow it must agree with the intended target — for example PQ/ST 2084 or HLG when that is the output being built. Selecting a wide gamut without the correct output transfer function does not create a valid HDR delivery by itself.

Output Gamma is part of the signal contract, not a visual preference
Do not duplicate a project-level HDR output transform
The viewer must interpret the HDR target correctly

Mapping controls

Contrast, Saturation, Middle Gray and Max. Luminance

These controls shape the NVIDIA HDR result after the colour-state contract has been defined. Do not use them to compensate for a wrong Input/Output Color Space or Gamma.

Contrast

Shapes the contrast response of the NVIDIA HDR mapping. Treat Resolve's numeric scale as its own control scale rather than assuming it maps 1:1 to NVIDIA App sliders.

Saturation

Controls colour intensity in the mapped result. Increase conservatively and verify saturated highlights against the target gamut/colour volume.

Middle Gray

Sets the midtone/reference placement used by the HDR conversion. It strongly influences perceived paper white and overall scene brightness.

Max. Luminance

Defines the intended peak luminance for the mapping. The default panel value shown here is 1000; validate the target against the actual mastering/delivery intent.

Global Blend

Mixes the OFX result with the incoming image. It is useful for creative moderation, but partial blend also mixes two different renderings, so use it deliberately in technical HDR work.

Production workflow

A six-step SDR→HDR pipeline that avoids double rendering

Confirm that the source really needs SDR→HDR expansion

RTX Video HDR is an AI-assisted SDR-to-HDR mapping tool. Do not put it on material that is already correctly mastered HDR merely because the output is HDR.

Lock the exact input signal state

Set Input Color Space + Input Gamma from the values actually arriving at the node. If upstream CST/RCM/DCTL has changed the signal, describe the changed state rather than the camera metadata.

Define one HDR target

Choose Output Color Space and Output Gamma so the OFX result matches the next stage or final HDR encoding. Avoid building a second conflicting output transform downstream.

Place middle gray and the peak before chasing saturation

Middle Gray sets the midtone/reference placement of the NVIDIA mapping, while Max. Luminance defines the intended highlight ceiling. Establish those anchors before creative Contrast and Saturation tuning.

Validate highlights, colour volume and skin

Use HDR waveform/scopes and inspect saturated highlights, signage, LEDs and skin. AI expansion can create a convincing image while still producing values that need gamut management or restrained creative settings.

Check the real HDR monitoring and delivery path

A desktop viewer shown through an SDR path can make a correct HDR signal look blown out or washed out. Validate the display transform, HDR monitor path, export colour tags and metadata separately from the OFX itself.

Do not confuse the jobs

RTX Video HDR versus CST, Gamut Mapping and manual HDR grading

Tool	Main role	What it does not replace
NVIDIA RTX Video HDR	AI-assisted SDR→HDR expansion with explicit input/output signal description	Project HDR delivery setup, monitoring, metadata or deterministic CST logic
Color Space Transform	Deterministic colour-space/gamma conversion plus selectable tone/gamut mapping	AI-assisted perceptual remapping of SDR appearance
Gamut Mapping	Tone/gamut remapping and saturation compression/clip within a known signal state	SDR→HDR content expansion or input/output colour-space conversion
HDR palette / manual grade	Creative zone-based grading and intentional highlight/midtone placement	Automatic AI mapping of the whole SDR image

Common failures

Most failures are signal-state or monitoring failures

Symptom

Highlights look blown out immediately

Cause: Input Gamma / Input Color Space does not describe the node input, or the HDR result is being transformed again downstream.

Fix: Set explicit input values, bypass downstream CST/DRT temporarily and verify which stage is performing the only intended SDR→HDR rendering.

Symptom

Midtones are too dim or paper white feels wrong

Cause: Middle Gray / Contrast are not suited to the intended HDR presentation, or the viewer is not showing the target transfer function correctly.

Fix: Verify the HDR display path first, then tune Middle Gray and Contrast while watching the waveform and a real HDR monitor.

Symptom

Neon and LEDs become unnaturally saturated

Cause: The AI expansion plus Saturation is pushing colours beyond a comfortable target colour volume.

Fix: Reduce Saturation, inspect vectorscope/CIE and use a deliberate Gamut Mapping stage if the delivery gamut needs compression rather than clipping.

Symptom

The effect is unavailable or an overlay appears

Cause: The system does not satisfy the NVIDIA RTX Video requirements used by Resolve.

Fix: Use DaVinci Resolve Studio on Windows with a supported NVIDIA RTX GPU and current supported driver. Blackmagic marks the effect as desktop Studio and platform-specific.

AI SDR→HDR, but only with a correct signal contract

NVIDIA RTX Video HDR: the signal-level model

NVIDIA RTX Video HDR is not merely another output CST. NVIDIA positions RTX Video HDR as an AI-assisted SDR-to-HDR conversion, while Resolve wraps that operation in explicit Input/Output Colour Space + Gamma controls and mapping parameters. The result therefore depends not only on the AI model but also on how accurately the signal is described before and after the OFX.

Blackmagic's current Studio feature matrix lists Nvidia RTX Video HDR as a desktop Studio Resolve FX with a platform note requiring Windows, a supported NVIDIA RTX GPU and driver. NVIDIA's RTX Video SDK describes the core task as AI-enhanced SDR-to-HDR tone mapping: Rec.709 SDR is expanded into HDR10-compatible Rec.2020. In the Resolve 21 panel, that operation is surrounded by explicit colour-state controls plus Contrast, Saturation, Middle Gray, Max. Luminance and Global Blend.

Keep three layers separate: the AI mapping inside RTX Video HDR, Resolve project/output colour management, and the real HDR monitoring/delivery path. The OFX does not configure mastering metadata, codec/container signalling or the monitor for you. It is not colorimetric restoration either: NVIDIA explicitly warns that expanding the SDR colour space can alter the source creative intent. If an RCM/ACES/CST output transform is already rendering the image, a second rendering stage after RTX can easily produce blown highlights or incorrect contrast.

Use it when

creating an HDR version from an SDR master/source when an automated AI-assisted starting point is useful
a fast SDR→HDR pass with explicit control of input/output colour state and target peak
workflows where AI expansion is then validated and refined with conventional HDR grading/gamut tools

Choose another tool when

the source is already correctly mastered HDR and no special creative remap is required
a strictly deterministic transform between known colour spaces/gammas is required — CST/RCM/ACES is usually more transparent
there is no supported NVIDIA RTX/Windows environment or no correct HDR monitoring path

Control → signal meaning → verification

Layer	What it means	How to verify
Input Colour Space + Gamma	Describes the actual gamut/primaries and transfer/encoding of the signal at the OFX input.	Audit source tags and upstream CST/DCTL/RCM rather than trusting Use timeline automatically.
AI SDR→HDR mapping	NVIDIA expands the SDR representation into an HDR-oriented result by remapping luminance/contrast/colour response through RTX Video HDR.	Viewer + HDR waveform + a real HDR monitor; compare skin, diffuse whites, speculars and dark detail.
Middle Gray	Sets the midtone/reference placement inside the mapping and therefore affects perceived paper/reference white.	HDR waveform and a real monitor; do not use it to compensate for a wrong output transform.
Max. Luminance	Defines the intended peak luminance used by the HDR mapping.	Check highlights on the target/nit scale and compare against mastering/display intent.
Contrast + Saturation	Creative/appearance shaping within the RTX-mapped result after the signal contract has been defined correctly.	Skin, vectorscope/CIE, saturated highlights and bypass. Do not transfer numeric presets from NVIDIA App 1:1.
Output Colour Space + Gamma	Describes the target representation that the OFX should hand to the next pipeline stage.	Make sure the downstream stage expects that exact pair and is not applying a second conflicting output rendering.

Production workflow

01Confirm that the source is SDR and that you are genuinely building an HDR version rather than remapping an existing HDR master.
02Lock the real Input Colour Space + Gamma at the node input.
03Define one target Output Colour Space + Gamma and make sure the project-level transform does not duplicate it.
04Set Middle Gray and Max. Luminance against the delivery target first, then tune Contrast/Saturation conservatively.
05Verify HDR waveform, skin, highlights, gamut/colour volume and the final monitor/output tags before delivery.

Diagnostics: symptom → cause → fix

Immediate blown highlights / clipped-looking image

Likely cause: Input/output gamma is described incorrectly or the HDR result is going through a second output transform.

Fix: Use explicit input/output values, temporarily bypass downstream CST/DRT and identify the single intended rendering stage.

Midtones are too dark or reference white is too high/low

Likely cause: Middle Gray/Contrast does not suit the target presentation or the monitor path is interpreting the HDR signal incorrectly.

Fix: Validate monitoring/output gamma first, then adjust Middle Gray and Contrast using waveform + HDR monitor.

Neon/LED/graphics become excessively saturated

Likely cause: AI expansion plus Saturation is pushing colour outside the target colour volume.

Fix: Reduce Saturation and, if needed, use a deliberate Gamut Mapping/limiting stage after checking CIE/vectorscope.

The effect does not work / an unsupported overlay appears

Likely cause: The Windows + NVIDIA RTX + driver environment is not supported or Resolve Studio is not being used.

Fix: Check Blackmagic's feature matrix and the NVIDIA RTX Video system requirements for the current Resolve/driver combination.

Node placement

Place RTX Video HDR where its Input Colour Space/Gamma can be described unambiguously and where the next target stage is under control. In a manual pipeline this is often a dedicated technical node/branch between a known SDR state and a known HDR state. In managed RCM/ACES, take special care not to add an implicit second output rendering after the OFX.

Scopes / validation

Validation requires HDR-capable waveform/HDR scopes, vectorscope/CIE for saturated colours and a real HDR monitoring path. Inspect diffuse/reference white, specular highlights, skin and saturated graphics together. An ordinary SDR viewer is not proof that the HDR rendering is correct.

Managed-pipeline warning

RCM/ACES may already perform scene-to-display rendering, tone mapping and gamut handling. If RTX Video HDR creates an HDR output representation and the project then runs another output DRT, the stages are stacked. Document which stage owns the SDR→HDR appearance and which stage is only responsible for encoding/delivery.

Do not confuse the roles

NVIDIA RTX Video HDR versus the neighbouring Color FX

Color Space Transform

explicit conversion between colour-space/gamma descriptions, including tone/gamut mapping

NVIDIA RTX Video HDR

The four dropdowns matter more than the creative sliders

Input Color Space

Input Gamma

Output Color Space

Output Gamma

Contrast, Saturation, Middle Gray and Max. Luminance

Contrast

Saturation

Middle Gray

Max. Luminance

Global Blend

A six-step SDR→HDR pipeline that avoids double rendering

Confirm that the source really needs SDR→HDR expansion

Lock the exact input signal state

Define one HDR target

Place middle gray and the peak before chasing saturation

Validate highlights, colour volume and skin

Check the real HDR monitoring and delivery path

RTX Video HDR versus CST, Gamut Mapping and manual HDR grading

Most failures are signal-state or monitoring failures

Highlights look blown out immediately

Midtones are too dim or paper white feels wrong

Neon and LEDs become unnaturally saturated

The effect is unavailable or an overlay appears

NVIDIA RTX Video HDR: the signal-level model

Use it when

Choose another tool when

Control → signal meaning → verification

Production workflow

Diagnostics: symptom → cause → fix

Node placement

Scopes / validation

Managed-pipeline warning

NVIDIA RTX Video HDR versus the neighbouring Color FX

Primary references used for this technical layer

Use the FX page for the tool; use Color Science for HDR theory

HDR

PQ / ST 2084

HLG

Tone Mapping

Practical questions about NVIDIA RTX Video HDR

Is NVIDIA RTX Video HDR just a CST?

Should Input Color Space/Gamma stay on Use timeline?

Is Max. Luminance the monitor brightness setting?

Does the plugin finish HDR delivery by itself?

Keep AI HDR expansion inside a controlled colour pipeline

Invert Color

Color Space Transform

Gamut Mapping

Camera Shake