Set the light. Keep your rhythm.
A native Windows remote for the monitors on your desk: brightness and contrast where supported, a per-display warmth tint, and presets you can make your own. From one window, or one command.
Poster around a uniformly reduced 1.5.0 development interface, with sample displays. The opaque reference omits desktop blur and the native window frame. Full-size interface · Source receipt · Artwork sources and receipt.
Start here: Download · Set up your desk · Troubleshoot · Contribute
Current source checkpoint: 1.5.0, unreleased. The published download is v1.0.0; its interface and features differ from the source shown here. Changes · Build and package status.
Find your level. Select a display on the desk map and adjust the controls it supports. Requested settings and hardware observations remain distinct.
Make a mode your own. Tune one screen, copy its estimated brightness and warmth into a mode, review the other displays, then save. Saving changes the preset; it does not adjust a screen.
Keep one screen, darken the rest. Night saver requests at most 5% of the retained display's hardware brightness range and covers the others. End Night saver requests their saved brightness back. Check the result on your desk.
An external monitor may not have a brightness slider in Windows. Microsoft's brightness guide points users to the monitor's own buttons when that slider is unavailable. LumenDeck brings supported monitor controls into one desk-wide interface.
LumenDeck talks to the monitors directly over DDC/CI, the control channel that rides the video cable and drives the same values as the on-screen menu. A laptop's internal panel can be handled over WMI. Available controls depend on the display, driver and connection; brightness and contrast are checked separately.
Runs as an ordinary user. No administrator rights, no drivers, no service.
lumendeck-cli --list # every monitor and what it will accept
lumendeck-cli --preset Night # level the whole desk for the evening
lumendeck-cli -m "left" -b 55 -w 5000| Brightness & contrast | Per monitor, over DDC/CI (VCP 0x10 / 0x12) |
| Warmth tint | Per monitor, 3000K–6500K software gamma target; not measured colour temperature |
| Presets targeting estimated luminance | Day / Evening / Night — choose brightness percentages using panel profiles; edit their targets |
| Preset schedule | Optional: request Day, Evening, Night or Custom at times you choose |
| Custom | Request your remembered manual levels per monitor; presets preserve those levels |
| Reversible screen blackout | Per-monitor black overlay plus minimum supported brightness; click or use an optional global shortcut to restore |
| Night saver | Keep one work display on at 5% hardware brightness or lower; darken the others with one click, then restore saved brightness |
| Precise adjustment | Click a slider's value or press F2 to enter an exact value; arrows adjust one hardware unit, Shift adjusts ten |
| Additional advertised controls | Input source, picture mode, speaker volume, sharpness, RGB gain, black level, factory reset — availability and behavior depend on the monitor |
| Desk map | Windows desktop positions, adjacency and pixel proportions; select a screen with the mouse or keyboard |
| Identify | Puts each monitor's name on its own glass |
| Laptop panels | Internal displays via WmiMonitorBrightnessMethods |
| Command line | Scriptable, with JSON output and meaningful exit codes |
| Material finishes | Smoke, Frost and Ceramic; Mica, Glass or Solid, with Windows high-contrast priority. Four palette themes remain in the classic panel |
| Tray app | Lives in the notification area; optional start-with-Windows |
LumenDeck works as a desk remote: choose a display, adjust its supported controls, check the observation, and restore when needed. The default material interface connects brightness, contrast, warmth, presets and Night saver to the same device controller, settings and recovery paths as the classic panel.
Night saver remains visible at the top. Display actions contains blackout, shortcuts and brightness estimates. Desk actions applies desk-wide presets and chooses the retained Night saver display. Settings opens preset targets, schedules, startup preferences and appearance choices.
The visible Theme button at the top offers Smoke, Frost and Ceramic. Smoke and Frost can use Mica, Glass or Solid; Ceramic stays opaque. Choices apply after a confirmed save without rescanning or changing displays. Compare finishes and classic themes.
Click an adjustment's value or focus its slider and press F2/Enter for exact entry. Arrows adjust one hardware unit (50 K for warmth); Shift makes ten-unit steps. Ctrl + Page Up / Page Down switches displays. Advanced controls (classic) opens the complete optional monitor controls; Settings > Material interface returns to the material window. The classic panel retains All displays and spatial map navigation. Read the functional interface guide.
Brightness distinguishes its requested value, last observed value, pending readback, matching readback and unconfirmed/failed requests. Contrast requests also expose their observation state. Readback is a reported hardware value, not a light measurement; WMI write acceptance alone remains unconfirmed. Switching selection never transfers a pending result to another screen. Warmth remains an explicitly labeled gamma tint target, and estimated nits stay secondary.
Smoke is the default material finish. Windows contrast themes use system foregrounds and surfaces. Unsupported native material or disabled transparency uses an opaque fallback. Shared editors keep their classic palette. See the interface design notes. If an adjustment fails or cannot be confirmed, its card keeps a notice with Connection help and Dismiss. Other actions and retries do not erase that history; dismissing the notice does not confirm the change. Refresh replaces the cards with the new scan, which also does not establish that an earlier request succeeded.
An identical brightness percentage can produce different amounts of light on different panels. A profile lets presets account for that difference instead of assigning every monitor the same percentage.
LumenDeck models each panel as nits ≈ floor + (peak − floor) × pct and solves
for a percentage targeting estimated luminance. For example, a 400-nit peak and
50-nit floor give approximately 200 nits at 43%; a 250-nit peak and 40-nit floor
give approximately 200 nits at 76%. These are model calculations, not readings.
Panels it has no profile for get a generic estimate, and the UI says it is an
estimate rather than presenting a guess as a measurement. Add your own in
%APPDATA%\LumenDeck\panels.json. Even measured profile endpoints do not prove
that a panel's entire brightness curve is linear or that two screens look alike.
Cards show Estimated nits with user profile or generic profile. A
profile's Measured flag means its author declares peak/floor instrument
measurements; missing flags default to false. Calculated nits are still estimates.
Choose Edit brightness estimate… on a card to edit peak/floor and sources,
and preview current estimated nits plus preset brightness percentages. Save
updates estimates and future presets without adjusting the screen. Profiles use
the full model name; identical models share a profile. The editor explains when
it starts from a broader match and lets you remove only the full-name entry,
with a preview of the next broader or generic profile. Existing files are backed
up in %APPDATA%\LumenDeck\profile-backups. For matching, conflict and backup
details, see profile editing.
A preset requests changes across the desk; Custom requests your remembered manual brightness, contrast and warmth. Manual slider changes update that monitor's Custom position, while Day / Evening / Night preserve it. Custom is not an undo history: moving a slider again replaces that monitor's remembered position. New monitors start with a Custom position from their initial readings. Changes save in the background; check Settings for a waiting or unconfirmed save. Inspect the screen and any card warnings after requesting a preset or Custom restoration.
To change presets by time of day, choose Settings > Preset schedule… and turn it on. It requests each period's preset once when the period begins (or after the first scan when LumenDeck starts during it); moving a slider or choosing another preset holds until the next scheduled time. It runs only while LumenDeck is running, and the notification icon shows the current period.
The built-in starting points are Day 160 nits / 6500 K, Evening 100 nits / 5000 K and
Night 60 nits / 4000 K. These are editable product choices for lit, softer and dim
rooms, not medically established comfort targets. Settings > Comfort guide
explains how to adjust for readable text, room light and colour work, with offline
research references. See the evidence and limits.
Choose Settings > Preset targets… to change them;
the editor previews the brightness percentage each connected display would
receive. Saving changes future preset requests only, in the window, tray and
lumendeck-cli --preset; it does not adjust a display or your Custom levels.
Make a mode from a comfortable screen: adjust one display with the sliders, then open Settings > Preset targets (or Display actions > Use this display in a mode in the material interface). Choose Use this display under Day, Evening or Night. It copies the selected display's estimated nits and current warmth into that mode's draft. Review the per-display previews, then save. Reset this mode restores only that mode's built-in draft; other edits stay.
The source is captured when the editor opens. Copying, resetting and saving do not adjust hardware. Capture is unavailable for blanked/Night saver displays, unsupported brightness, pending or failed readback, or an unusable estimate. Restore or check the display and reopen the editor; numeric editing remains available. Cross-display matching and round-tripping through whole-number nits are estimates, not a promise of identical brightness or appearance.
See the personal preset editor · How capture and saving work
The obvious way to reduce blue light is the monitor's own RGB gain registers. A monitor can advertise those registers and ignore every write to them. That was measured here, not assumed: on one of the panels this was built against, sweeping blue across the full 0–100 range returned an unchanged value thirteen times in a row while every call reported success. That same panel offers no warm colour preset at all — only 6500K and cooler.
So warmth is applied as a per-display GPU gamma ramp, composed on top of the captured or stored baseline ramp. Turning warmth off requests that baseline again. This preserves the baseline data rather than replacing it with an identity ramp; it is not a guarantee of complete ICC, HDR or driver compatibility. Other colour tools can overwrite the ramp, and unreadable baselines can prevent reliable restoration. Check the result on your own display.
LumenDeck provides a separate warmth setting for each display.
The Kelvin value is a requested tint using an approximate gamma-2.2 model, not a
measurement of the display's white point. test\Test-Gamma.ps1 independently
reads the GPU ramp and checks its model-implied tint; it cannot measure emitted
light. Physical colour temperature requires an instrument and depends on the
panel, calibration and rendering pipeline. See docs/notes.md.
\\.\DISPLAY1, 2, 3… is not a stable identity. The numbering carries gaps
from past hot-plugging, and it need not match the number Windows paints during
Identify. Acting on a guessed mapping adjusts the wrong monitor and looks
exactly like success.
LumenDeck labels monitors by model and physical position, keys saved settings on EDID identity (falling back to the physical port when two panels are truly identical), shows your desk schematically, and has its own Identify.
This README describes the current source. Check the release notes for the features included in a downloaded version; changes under Unreleased in the changelog are not yet part of a published download.
Download the attached app files from Releases. The published v1.0.0 offers separate self-contained executables. Its attached release notes describe that download; the current development source includes additional features described throughout this README.
LumenDeck discovers each control separately. A missing contrast slider does not mean that brightness or the whole connection failed. These are the current source's control paths, not a tested-device list or a promise for every panel:
| What you want to change | What it depends on | First check |
|---|---|---|
| External-monitor brightness or contrast | DDC/CI support in the monitor and a connection that passes its commands | Enable DDC/CI in the monitor menu if available. If using a dock, hub or KVM, try a direct video connection. |
| Built-in-panel brightness | A brightness interface exposed by the laptop's Windows driver; LumenDeck uses WMI as a fallback | Try the Windows brightness slider. If it is missing too, check the manufacturer's display-driver guidance. This WMI path does not provide hardware contrast. |
| Per-display warmth | GPU gamma-ramp support; restoration uses a captured or stored baseline | Check the visible result. An unreadable baseline can prevent reliable restoration. HDR, calibration tools and drivers can affect behavior; full ICC/HDR compatibility is not established. |
| Screen blackout / Night saver | A black overlay, with minimum hardware brightness when available | Restore one screen and verify its brightness before relying on a whole-desk setup. Without brightness support, the overlay still works; it does not turn the monitor off. |
Open Connection help in a build that includes it for the observed controls and recovery steps. After changing a cable or monitor setting, choose Refresh; it can also reapply saved warmth and retry active blackout recovery. Start with one display before changing the whole desk.
Two executables:
LumenDeck.exe |
the window and the tray icon |
lumendeck-cli.exe |
the command line |
- Separate EXE assets: download
LumenDeck.exeinto a folder you want to keep, then open it. Downloadlumendeck-cli.exetoo if you want command-line controls. No extraction or separate .NET runtime is needed. - Portable ZIP: if the release offers an app ZIP, extract the whole archive,
then open
LumenDeck.exe. GitHub's automatic Source code archives contain source files; build those using the instructions below.
The development portable package includes offline QUICKSTART.txt, the MIT
licence and SHA256SUMS.txt. A separate .zip.sha256 records the archive hash.
Hashes detect changed files; they do not establish the publisher's identity.
Packages are currently unsigned. Choose Settings > About LumenDeck for
version/build and offline help when your build includes that entry.
If Windows Security detects malware or blocks the download, stop and read download security. An unsigned-app reputation prompt and an antivirus detection need different investigation; a matching checksum does not clear a malware detection.
Settings live separately in %APPDATA%\LumenDeck; portable distribution does
not mean settings are saved beside the executable. Exit from the tray menu
before replacing or moving app files so any blanked screens can be restored.
Opening LumenDeck.exe or its shortcut again reveals the existing control
window. It keeps one app instance; relaunching does not scan or adjust a monitor.
If startup or different permissions prevent the request, use the existing
notification-area icon and run both copies with normal user permissions.
Settings in the window exposes Windows startup, minimised launch, closing to the notification area and saved-warmth reapplication. The tray's startup switches stay synchronized. Local preferences save in the background; checks stay at the active preference until completion, and an unconfirmed save retains it. Local preference options are temporarily disabled while saving. The Windows startup switch shows registration readback or an explicit unavailable state. Start minimised affects the next launch; with keep-running off it starts on the taskbar. Warmth reapplication affects the next display scan and does not adjust the current screen when toggled. Use tray Exit to quit when keep-running is enabled. While a settings save is pending, wait for it to settle before using Exit again. See preference behavior for storage and verification details.
The GUI and CLI are separate binaries on purpose: a GUI-subsystem process cannot stream stdout back to the shell that launched it, so a single executable pretending to be both prints nothing when piped.
For builds with the controls described here, start with one display before changing the whole desk:
- Choose Identify and match the physical screen to its card. If a display or slider is missing, open Connection help before adjusting another card.
- Note its current brightness, then move that card's brightness slider a small amount. Check the screen and card warnings. To return to the earlier value, move the slider back; Custom now remembers the new manual position.
- Once your manual levels are comfortable, try a preset on one card. That card's Custom requests its remembered manual levels. The All monitors commands apply across the desk, skipping blanked displays.
- To darken unused screens, select your work display in Keep working on, then choose Night saver. Use End Night saver for those screens; screens blanked individually retain their own restore controls. Verify the screens after restoration.
Closing the window normally keeps the app in the notification area when Keep running when closed or minimised is enabled. Open the executable again to reveal it, or use tray Exit to quit. Before replacing app files, restore blanked screens and exit normally.
git clone https://github.com/snowyukitty/LumenDeck
cd LumenDeck
dotnet build LumenDeck.slnx -c Release
powershell -File install.ps1 # installs, shortcuts, adds to PATHNeeds the .NET 10 SDK. install.ps1 -Uninstall removes the installed executables and integration entries.
The installer refuses to install or uninstall while LumenDeck is running. Exit through the tray menu first. Uninstall preserves settings and unrelated files in the app directory.
To build a verified portable ZIP locally:
powershell -NoProfile -File scripts\build-release.ps1Each run preserves earlier builds and prints the new ZIP path under dist/.
See packaging verification for checks and limitations.
--list Every monitor and its current settings
--json Machine-readable output
--features Extra controls each monitor advertises
--diagnose Observed capabilities and response details
--support-report Minimal support details with names and IDs excluded
-m, --monitor <text> Only monitors whose name, position or device matches
-p, --preset <name> Day | Evening | Night | Custom
-b, --brightness <n> 0-100, or a relative step: +10, -10
-c, --contrast <n> 0-100, or a relative step: +10, -10
-w, --warmth <kelvin> 3000-6500, or "off"
-v, --version Version
Exit codes: 0 done, 1 invalid request or nothing matched, 2 a monitor change
or settings save was unsuccessful (also used for withdrawn --power), and 3
an unexpected command failure — so
it can be used in a scheduled task or bound to a hotkey by whatever launcher you
already use.
The complete request is checked before settings or display access. Unknown,
missing or duplicate options, invalid presets, absolute percentages outside
0–100 and warmth outside 3000–6500 fail before any earlier adjustment is sent.
Use one information command at a time and keep it separate from adjustments;
--json belongs with --list or --support-report. Multiple adjustment options
can be combined. Signed brightness/contrast steps such as +10 or -10 still
stop at the display's limits. Valid requests can encounter hardware or storage
failures after execution starts; validation does not make monitor writes atomic.
If the GPU rejects a warmth request, the CLI returns 2 and reports Requested
instead of Applied. It keeps the previous current/saved warmth and Custom
temperature. Other accepted adjustments in the same command may already have run.
Every monitor card also has Blank screen / Restore screen and Set shortcut. Blank screen draws a borderless black window over that one display and lowers it to its minimum supported brightness. Click the black screen, press a key while it has focus, use the global shortcut, or exit LumenDeck to request restoration of the exact saved brightness. An interrupted blackout is retried automatically on the next launch; unavailable displays retain recovery data. Verify the screen after restoration.
This is deliberately not MCCS hardware-off. Some monitor firmware switches off
the DDC receiver while processing VCP D6=04, making the matching wake command
impossible and requiring a physical power button or power-cable reconnect.
LumenDeck therefore never exposes DDC-off through its window, shortcuts, generic
controls, or CLI. On an LCD, a black image cannot save as much power as a true
backlight-off state; reversibility takes priority. A display without software
brightness control still gets the black overlay.
Press Night saver in the toolbar or tray menu. The Windows primary display is kept on by default; change and remember that choice under Desk actions… > Keep working on. Its brightness is requested at 5% of its hardware control range, rounded down to a supported unit. A display already darker stays unchanged. This low target is independent of the Night reading preset. It is not measured light output: a panel's minimum brightness still limits how dark it can get. Displays without brightness control stay unchanged, with a warning. Other screens get a black overlay and their lowest supported hardware brightness. End Night saver attempts to restore the saved hardware brightness values, including the work display's and values on panels with ranges such as 0–255. Screens you had already blanked individually stay under their own restore controls. The work display's original brightness is saved before it is dimmed, so exiting, or the next launch after a crash, puts it back. If you manually change the work display's brightness during the night (slider, preset or Custom), your choice wins and ending the night leaves it alone. Automatic presets and scheduled Custom skip the dimmed work display, keeping its brightness, warmth and recovery snapshot. They resume their ordinary behavior at the next period after you end Night saver. Night saver does not put Windows to sleep.
You can restore one screen by clicking its black overlay or using its existing shortcut. Refresh keeps remaining blackouts in place; exiting attempts restoration. An unavailable display retains its recovery data for the next reconnect or launch. Displays attached after entering Night saver are left visible so a new work screen is never unexpectedly hidden. Presets skip blanked displays, and their brightness slider is disabled until restored.
This reduces light and can reduce backlight power; actual energy savings depend on the panel. A black LCD still has its backlight on. LumenDeck does not claim a measured watt reduction or use a hardware-off command that may prevent wake.
Press F1 in the main window, or choose Settings > Keyboard controls…, for the offline reference. In that guide, Page Up / Page Down scroll and Home / End go to the start / end; Escape closes it.
In the main window, Ctrl + Page Down / Page Up selects the next / previous display card in layout order, wrapping at either end. Selection keeps the same available control, otherwise brightness or warmth, and scrolls into view. From the toolbar, next enters the first card and previous the last. These keys move selection without adjusting a display; navigation pauses during reading.
Slider adjustment keys and F2 / Enter do not act while Ctrl or Alt is held. This keeps command combinations from accidentally changing a display or opening an exact-entry draft. Ordinary keys and Shift adjustments still work.
Focused command buttons activate with Space or Enter. Moving focus away before releasing cancels that press; disabled buttons remain unavailable.
Refresh preserves selection on the same display/control when its card is replaced. A new selection during reading takes priority; a removed display or unavailable control returns selection to Refresh. The selected card control is scrolled into view, including in a short window.
Click a slider's number, or focus it and press F2 or Enter, to type an exact value. The dialog shows the display/control, unit and valid range in its body. Apply sends a request; Cancel or Escape leaves that entry unapplied. Refresh replacing the card or disabling its control cancels the open entry.
Brightness and contrast use the hardware's reported range; brightness's usual readout remains a normalized percentage. Warmth accepts Kelvin directly (3000–6500; 6500 restores the neutral profile).
Arrow keys and wheel notches move brightness or contrast by one hardware unit. Shift multiplies the step by ten; warmth uses 50 K steps. Home / End go to the range limits, and Page Up / Page Down make larger adjustments.
# dim everything a notch
lumendeck-cli --brightness -10
# warm only the screen on the left
lumendeck-cli -m left --warmth 4600
# -m narrows what is shown, too
lumendeck-cli --list -m left
# and back to your own levels on every screen
lumendeck-cli --preset Custom
# feed it to something else
lumendeck-cli --list --json | ConvertFrom-JsonIn --list --json, estimatedNits is a model result (or null when brightness
is unavailable) and nitsAreEstimated is always true. luminanceProfile is
user or generic; profileEndpointsMeasured preserves the user-declared
endpoint flag, not verification of current light output. Earlier versions could
report nitsAreEstimated: false simply because a user profile matched. Consumers
that relied on that meaning should use luminanceProfile for profile selection.
Strict JSON consumers must also allow the two new metadata fields.
These are documented workflows, not an exhaustive feature or compatibility matrix. Alternative projects' documentation was checked on 2026-10-08; follow the linked sources for current features and requirements.
| Tool | Documented workflow |
|---|---|
| LumenDeck | Desk map, per-display warmth, estimated-luminance presets, reversible blackout and a standalone JSON-capable CLI. Optional preset scheduling while the app runs. Hardware controls depend on the display and connection. |
| Twinkle Tray | Its own system-tray brightness flyout, hotkeys, scheduled or idle brightness changes and DDC/CI controls including contrast. Its command-line options also include VCP writes and require the app to be running. |
| Monitorian | Brightness control for multiple monitors. Its Store add-ons include hotkeys and command-line brightness/contrast controls on a subscription basis. |
A monitor is missing, or its sliders are greyed out. Open Connection help in the window, or Why are controls unavailable? on the monitor card, for offline checks. When no cards appear, the window distinguishes reading, a completed scan with no displays and a failed scan. Its state card offers Connection help and manual Refresh; adjustments wait until current cards are available. Refresh may reapply saved warmth and recover active blackouts.
The offline guide shows which hardware controls responded, separates external-monitor checks from built-in-panel guidance, and offers next steps when no displays were found. A missing contrast control does not mean that brightness or the whole DDC connection failed.
For the running version and build, choose Settings > About LumenDeck >
Copy version and paste the two lines into your issue. This explicit action
copies only the GUI version/build, without display or device details.
If your download has no About entry, use lumendeck-cli --version or name the
release you downloaded. If it has no support-report command or preview, describe
the issue and leave that optional field blank; raw diagnostics are not required.
The published v1.0.0 download has inconsistent embedded version labels:
the GUI reports 1.1.0, while the CLI reports 1.0.0. If you use that download,
include the release tag and the reported version when opening an issue. Current
builds use one shared version and verify both executables before packaging.
For an issue, choose View support report in Connection help and review the
exact preview before pressing Copy report. The CLI equivalent is
lumendeck-cli --support-report (or add --json). It includes version, observed
control availability and raw ranges, while excluding names, serials, device
identifiers, paths and raw logs. Nothing is uploaded. Counts and ranges still
describe your setup; this is not a guarantee of anonymity.
The CLI report command performs a fresh read-only scan, without loading or
saving gamma-baseline records or adjusting display settings. Use it alone or
with --json; mixing it with adjustments or a monitor filter is rejected.
A completed scan, including zero displays, exits 0; invalid combinations exit
1, and a failed scan exits 2 with a report whose scan state is failed.
The GUI preview uses the most recent app scan and performs no new hardware I/O.
Advanced lumendeck-cli --diagnose includes device identifiers and raw details;
review and redact it before sharing. Common things to check:
- Check whether DDC/CI is enabled in the monitor's own menu; consult its manual.
- Try a direct connection if you use a dock, hub or KVM. Connection paths can affect DDC access; an unavailable control alone does not establish the cause.
- For a built-in laptop display, check OEM/driver brightness support. Its WMI brightness path is separate from external-monitor DDC/CI.
Brightness changes, but nothing else does. Controls can be independently
unsupported, blocked or ignored. --features shows advertised capabilities,
which do not prove that a write took effect. This symptom can also be an app
or driver bug. Check the monitor's menu and report the requested action, observed
result and support report rather than assuming a firmware cause.
The warmth reverts after a reboot. GPU gamma ramps can reset after a reboot, display mode change, driver restart or game transition. In Settings, enable Reapply saved warmth after a display scan to request saved warmth on startup and subsequent scans. Start with Windows independently requests launch at sign-in; it does not enable warmth reapplication. Changing either switch does not adjust the current screen. Check for a failure notice and verify the screen after the next launch or scan. See preference behavior.
Windows still shows the old icon. Confirm that the shortcut points to the new executable first. A stale shell icon cache is another possible cause.
%APPDATA%\LumenDeck\
| File | |
|---|---|
settings.json |
colour temperature and your Custom levels per monitor, keyed on EDID identity |
panels.json |
your own panel luminance profiles; an example is written on first run |
gamma-baselines.json |
saved baseline ramps and applied signatures used for warmth restoration — see below |
error.log |
only if something throws |
diag.log |
only when LUMENDECK_DIAG=1 |
Settings saves preserve a file changed by another writer instead of replacing it with an older whole-document copy. On a conflict, quit and reopen LumenDeck before saving again; on a busy writer, retry once it finishes. If a file could not be loaded, the app uses session defaults and preserves the original. Preferences and new blackouts cannot be confirmed saved in that state. See settings storage and recovery before repairing or resetting a file that may contain blackout recovery records.
gamma-baselines.json is the one file worth understanding. A GPU gamma ramp
outlives the process that set it, so an app that simply reads the ramp at
startup cannot tell your display's own state from the warmth it left there
yesterday — and one that gets this wrong composes warmth onto warmth until
"Warmth off" no longer means anything. LumenDeck stores the untouched ramp plus a
signature of what it last wrote to recognise matching ramps. Back up this file
before changing it: deleting it can lose a calibration baseline that cannot be
reconstructed from a tinted ramp. Shape-based fallback helps with simple ramps
but cannot guarantee recovery of an arbitrary calibration.
Set LUMENDECK_ANONYMISE=1 to replace monitor names with Display A, B, C
in the window, in --list and in --diagnose. This hides friendly names only;
raw diagnostics still contain device identifiers and other details. Review any
screenshot or diagnostic before sharing, or use the minimal support report.
The luminance profiles still match on the real name.
The design combines reversible controls with careful monitor I/O.
docs/notes.md covers
a physical monitor handle that is legitimately 0, why SetVCPFeature returning
success proves nothing, why working set is the wrong instrument for finding a
leak, why colour temperature has to compose rather than overwrite, how a setting
with no way to set it went straight to a stack overflow, and how two version
numbers agreed with each other while both came from the wrong place.
Contributions welcome — see CONTRIBUTING.md. Panel profiles with sources and measurement conditions are especially useful. For code changes, start with the architecture and extension map, then follow the focused verification route for the behavior you change.
The current milestone checkpoint records implementation scope, verification and the remaining real-monitor acceptance work before a release.
Keywords: Windows monitor brightness control, external display brightness, DDC/CI, MCCS, VCP, multi-monitor brightness, per-monitor colour temperature, blue light filter, night mode, contrast control, monitor input source switching, KVM, tray app, command line, C#, .NET, WinForms, f.lux alternative, Twinkle Tray alternative, Monitorian alternative, Windows 10, Windows 11.
MIT. See LICENSE.