Special K’s HDR Retrofit feature works on Windows 10/11 and can retrofit HDR support in most DirectX 11-12 games by forcing an scRGB 16-bit swapchain buffer and undoing the SDR compression of the internal tone mapper of the game with its own user-configurable tone mapper.
For native DirectX 11 games, Special K even supports remastering 8-bit, 10-bit, and 11-bit render passes as well as compute passes to further enhance the end result of the HDR retrofit process, plus an Adaptive Tone Mapping option is available.
HDR retrofit support in DirectX 12 and OpenGL is more limited. In DirectX 12 and OpenGL, Special K can undo the SDR compression of the internal tone mapper of the game with its own user-configurable tone mapper, but Adaptive Tone Mapping and remastering options may not work or may not be available.
Various HDR presets are available along with an HDR Visualization feature that visualizes the brightness output of the game in various ways.
A. Your display must support HDR.
B. HDR must be ON in Windows Desktop.
C. HDR Retrofit only works in D3D11, D3D12, and OpenGL (and possibly D3D9 games…)
Step 1. Launch a D3D11, D3D12, or OpenGL game (or possibly a D3D9 game…)
Step 2. Configure the game to run borderless fullscreen for max. compatibility.
Step 3. Display Special K’s control panel menu (Ctrl + ⇧ Shift + ← Backspace)
Step 4. Open the
HDR menu at the top of Special K’s control panel menu and press the
HDR Setup button.
Step 5. Select the
scRGB HDR (16-bit) option from the HDR Calibration widget that appears on the top-right side of the screen.
Step 6. Restart the game.
HDR10mode is experimental and works better for games that use
DLSS3 Frame Generation. You may also use this mode to remaster the pipeline for Native HDR10 games (DX11 only).
Most options in Special K have tooltips that appear upon hovering your mouse cursor over them.
HDR Menu and press the
HDR Setup button to open the HDR Calibration widget, and then, on the Right side, select
HDR Preset 0
Profile Display Capabilities and use the provided image inside to set the Clipping Point where you can see a pure white screen and press
On the Left side, use the
Brightness Scale slider to adjust to your
cd/m2 value according to your display’s capabilities.
To prevent brightness from frequently being reduced when using a display with an Automatic Brightness Limiter (ABL), we suggest you set
Brightness Scale to a fraction of the max brightness value as calibrated in Profile Display Capabilities:
2/3 of max
1/2 of max
Once you are satisfied with your settings, you can press
Exportto save your current HDR config. When Enabling Special K’s HDR in a different game, you can simply select Preset 0 or 1 and press
Importto load your saved values.
|Middle-Gray Contrast||Adds or subtracts contrast from typical flesh-tone content
|Bypass sRGB Gamma||If your game appears absurdly dark, it probably uses sRGB gamma
|[Reset]||Resets the currently selected HDR Preset to the software default
|[Export]||Exports the current profile’s settings to
|[Import]||Imports settings from
Make use of [Export] and [Import] to save and load custom HDR configurations
These control luminance response when processing HDR
Converts SDR to HDR
- The main tonemap mode, this is where the magic happens.
- Use this if your goal is converting a game from SDR to HDR
Also used for scRGB Bypass
Use only in games that are native HDR.
- Intended to analyze HDR quality in games, but has some potential for image adjustment.
- Required if you want to use SpecialK’s screenshot features along side a game’s Native HDR
A raw HDR swapchain with no post processing. Made to be used with Reshade.
Do not use this by itself!
If you don’t want to use SpecialK’s tonemapper, but something like Pumbo’s Advanced AutoHDR or Lilium’s Invesrse Tonemapper, you’d use SpecialK in Raw Framebuffer mode along side a Reshade shader of choice.
Pipeline remastering is a feature of Special K’s HDR retrofit that increases the range and precision of intermediate render passes to infuse/preserve HDR qualities early in the render pipeline rather than try to produce an HDR image using a game’s final output alone (i.e. Xbox Auto-HDR).
Remastered passes include things like atmospheric scattering, HDR (pre-tonemap) light accumulation, and (unfortunately) shadow maps and FMVs. Not all passes work as intended when their range and precision are increased, and the performance cost of upgrading these render passes varies from game to game.
Special K has disabled all of the render pass remastering options by default, since they were the source of many compatibility issues.
However, remastering is important for image quality and, in some games, even required for the UI.
You are encouraged to enable these yourself, they just cannot be the default policy or support requests from first-time users would never end
Consult the HDR Remaster Database for community collected information of known game and remaster option combinations.
Special K displays statistics in the Remastering Tooltips upon hovering over each Remaster element:
With these two additions, you know:
Remastering does have a performance impact, but it is difficult to measure.
The underlying SDR -> HDR process without remastering has virtually no performance overhead.
This visualizes image brightness versus the maximum luminance your display can process across the entire screen.
It is acceptable to exceed the range of this visualization, but ideally you would limit the pixels too bright for Max-Avg-Y to less than half the screen.
This visualizes image brightness versus the maximum luminance your display can process in a 10% local window. This is your display’s ability to handle HDR highlights, and it can only guarantee this level of performance in small localized regions. Obeying this limit is important or atmospheric bloom will inevitably wash out image detail that existed in the original SDR image!
Any solid color produced by either of the EDID visualization modes is a luminance level your display is capable of displaying without using smoke and mirrors. What you need to watch out for are color cycling pixels, they are out-of-range for your display and you must dial-back luminance settings or you will lose image detail.
Color cycling pixels are too bright for your display; they will not be clipped (unless in HGIG mode), but will cause the image to be processed differently.
¶ Default INI that will Enable HDR in all Games Automatically
(how good an idea this is, is up for debate)
To define default HDR values:
2. Place select INI tidbits from the game you just configured in
[Render.DXGI] UseFlipDiscard=true [Render.OSD] ;HDRLuminance: 1.0 = 80 cd/m^2, 9.375 = 750 cd/m^2 HDRLuminance=9.375 [SpecialK.HDR] scRGBLuminance_=18.75 scRGBGamma_=1.0 ToneMapper_=1 Saturation_=1.0 MiddleGray_=1.25 Use16BitSwapChain=true AllowFullLuminance=true Preset=0
That works for any other aspect of Special K configuration as well, so if you wanted SK’s framerate limiter everywhere, that is how you would do it.
If using a local DLL (e.g. dxgi.dll) to inject Special K, the default INI will be called default_dxgi.ini
You may either Apply Preset or Reset, the latter will give you a completely clean config and then automatically apply preset upon launching game.
Thanks to Lilium for the DXVK fork focused on HDR.
d3d9.dllfrom the archive depending on whether your game exe is 32 or 64bit (consult PCGamingWiki), and place the dll where the game’s primary
.exefile is located.
dxvk_d3d9.conffile to the same place as the DLL and rename the file to
If there are rendering issues, you will have to consult DXVK HDR Mod Readme and edit the dxvk.conf for your game and tweak the render targets until it renders as it should
Starting from v21.03.20, Special K added support for hiding HDR support from games so they do not enable their own HDR. This is useful for games that have poor quality native HDR with no in-game option to turn it off, and can allow the full use of Special K’s HDR retrofit in those titles which may result in a better HDR experience.
HDR Menufrom the top of Special K’s Control Panel
Disable Game's Native HDR