Guides

Quick start

1. Install

   Download the self-contained installer, GloamApp-win-Setup.exe: it installs per-user with no administrator prompt, bundles ArgyllCMS, and updates itself in the background. Prefer no install? Grab GloamApp-win-Portable.zip instead, extract it anywhere, and run the executable (it does not auto-update). Either way, Gloam lives in the system tray. Both links always give you the current release; the releases page has notes and checksums.

   Right-click the tray icon and enable Start with Windows so your corrections restore automatically at every boot.

   Seeing "Windows protected your PC"? That is Microsoft SmartScreen, not a problem with the download. Gloam is code-signed (click More info to see the verified publisher David Torcivia), but SmartScreen separately weighs download reputation. New signed apps can show reputation warnings until enough people have installed them. Click More info, then Run anyway.

2. Set your gamma (no meter needed)

   Right-click the tray icon: each monitor is listed with its real name. Pick a gamma mode per monitor:

   • Gamma 2.2: general PC use, most content. Start here.
   • Gamma 2.4: BT.1886, dark-room viewing, film mastering.
   • Windows Default: native piecewise sRGB (bypass).

   Global hotkeys switch the focused monitor without opening the menu: Win+Shift+F1 for 2.2, Win+Shift+F2 for 2.4, Win+Shift+F3 for Windows default, and Win+Shift+F4 for panic mode, which clears all gamma tables immediately. Win+Shift+N toggles night mode, and Win+Shift+G opens Game Lab for the active game.

3. Set up night mode (no meter needed)

   Night mode warms the white point to cut blue light in the evening. It composes on top of your gamma correction and any installed calibration, and it works the same whether or not you ever calibrate.

   The Night Mode button cycles between Off, Auto, and Manual. Off disables warmth entirely, Auto follows your configured schedule, and Manual holds your selected temperature immediately. Win+Shift+N is a separate quick toggle that temporarily disables or restores warmth without changing your button choice; it does not persist across restarts, so night mode always comes back on the next boot.

   Open Settings from the tray to configure the schedule. Each point fixes a target Kelvin and the duration of the fade into it; triggers can be a fixed time, sunrise, or sunset, computed from your latitude and longitude with optional ±120-minute offsets. Fades run in mired space and pace themselves against a perceptual threshold, so a long slide into warm white stays smooth rather than stepping.

   The rendering algorithm decides how the warm white point is computed:

   • Perceptual (the default) eases the white point partway toward warm, so colors stay close to normal while blue is cut. A strength slider controls how far the adaptation goes.
   • Accurate (CIE 1931) applies a full-strength black-body white point. It is colorimetrically exact but strongly warms and desaturates the whole image.
   • Ultra Night (amber) cuts roughly 90% of blue and most of green for maximum circadian protection. It is not color-accurate and is meant for the darkest part of the evening.
   • Classic is a traditional photo-style warm tint.

   If you care about the biological effect rather than the look, set a melanopic dose ceiling on the schedule. Gloam then picks the least visible combination of extra warmth and dimming that keeps the screen's melanopic light at or under your target, scored in CAM16-UCS so the change stays perceptually small. Typical evening targets land around 10 to 30 mel-lx; for melatonin sensitivity, under 10.

   The dashboard's Circadian light (melanopic) panel shows the current screen dose and this evening's cumulative exposure. When a panel spectrum is available the estimate uses it directly; otherwise Gloam falls back to generic primaries and marks the wider uncertainty.

   Application exclusions are a night-mode auto-disable list: while a listed application is in the foreground, night-mode warmth is turned off, either on every monitor or only on the displays its window covers. Your gamma correction and any installed calibration profile stay active; only the warm shift is suspended. This is useful for color-critical work in the evening, when you want neutral white on the working display without disabling night mode everywhere.

   Per-monitor temperature offsets live in Settings too. Use them to visually match displays to each other; observer metamerism means two panels can measure alike and still look different side by side.

4. Set up Game Lab

   Press Win+Shift+G while a game is active. Add that executable, or scan local Steam, Epic, GOG, and Xbox library metadata and choose a title yourself. Scanning never enables a profile automatically.

   • Reference keeps measured correction and the monitor's normal gamma.
   • Competitive Clarity lifts the deepest shadows while protecting the midtones.
   • Cinematic HDR preserves the HDR path and requires an HDR signal.
   • Night Ops uses the spectral night renderer for dark-room play.

   Leave Gameplay Lock on if you want the resolved scheduled color temperature to stay fixed during the session. The active receipt shows which game, display, calibration, gamma, shadow lift, and night policy are actually in force.

5. Live with it

   Your gamma preference and night mode compose on top of the installed calibration. Settings and window sizes persist per monitor and restore on startup, along with the corrections themselves, so a reboot, display change, resume from sleep, or a game resetting the ramp all settle back to your chosen state without intervention.

   Settings, reports, corrections, diagnostics, and logs are saved under %LOCALAPPDATA%\Gloam. Use Export Diagnostics from the tray when reporting issues.

6. Calibrate (colorimeter required)

   The steps above cover everything most users need. Calibration is for when you have a meter and want a measured, verified profile installed at the Windows level.

   Connect your meter and open Calibrate Display from the tray.

   • Pick the monitor, display type, and target. For an HDR desktop run, use HDR Desktop PQ (sRGB gamut). The setup page checks that Windows is in the matching SDR or HDR mode before measurement.
   • Select a meter spectral correction matched to the panel. Find online searches the DisplayCAL community database. The same browser can measure a new .ccss with a spectrometer or build a .ccmx from a reference spectrometer and colorimeter.
   • Choose Place Probe to position the shared patch surface on the intended display. The same placement window is reused by calibration, verification, refinement, characterization, trust checks, and correction capture.
   • Start the run. Gloam suspends its temporary rendering and measures with the intended calibration bypass. On HDR displays it also emits true HDR-range patches through a DirectX FP16 surface at exact PQ positions.

7. Verify the installed result

   When the run completes, Gloam installs the profile and measures through it. The report compares native and calibrated dE2000, shows tone and gamut charts, and records the exact profile and signal state used for the run.

   Enable detailed verification for error distributions and the worst-patch list. HDR verification adds neutral PQ tracking in absolute nits plus colored R/G/B/C/M/Y patches scored with dE ITP. The report keeps its JSON snapshot and raw CSV data in history; export a printer-friendly PDF when you need a portable record.

   Use the report's toggle control for an immediate A/B. If activation is suspect, treat the measurements as diagnostic evidence and resolve the profile association before judging the calibration.

8. Refine, characterize, and track

   For a live HDR report with its profile enabled, Refine → HDR tone + color runs a coordinated closed loop over neutral and colored HDR patches. It keeps the best measured state, limits the solve to two passes, and refuses unsafe or non-improving changes.

   After a successful refinement, Gloam re-verifies through the new profile and rebuilds the report. The numbers, charts, saved JSON, raw CSV files, and later PDF exports therefore describe the refined calibration rather than the original run.

   Characterize HDR measures the panel's true peak, clipping or roll-off knee, and APL/ABL behavior with extra samples near the top end. Trust Check is a short six-patch recheck that trends average error and white-point drift, exports CSV, and can remind you monthly without committing you to a full recalibration.

How Game Lab stays out of the game

Game Lab watches the normal Windows foreground-window state and resolves a saved display profile outside the game process. It does not inject a DLL, hook a swap chain, draw an overlay, or inspect game memory. Executable paths are validated before they can become profiles, and shell or system executables are filtered from discovery.

For borderless or windowed games that span displays, Gloam applies the profile only to the screens covered by the game window. Local signal checks report the expected SDR/HDR mode, DXGI color space, bit depth, HDR headroom, and measured-calibration status. These are observations of the Windows display chain, not claims about a game's internal renderer.

Edits save and apply automatically. Disable the profile to compare against your normal desktop state, or press the panic hotkey at any time to clear live gamma ramps. Calibration and verification temporarily bypass game rendering so a foreground profile cannot contaminate measurements.

Calibration best practices

A colorimeter reports what it sees. These habits make sure what it sees is your display's steady-state behavior and not a transient, a reflection, or a meter artifact.

Warm the panel up

Displays drift as they reach operating temperature, and OLEDs especially so: white point and luminance can shift noticeably during the first stretch of operation. Run the panel for at least 30 minutes showing varied content before measuring. Calibrating a cold OLED means calibrating a state the panel will not be in an hour later.

Darken the room

Ambient light leaking around or through the meter contaminates dark-patch readings, which is exactly where HDR calibration matters most. Measure in a dark room, kill direct light sources facing the screen, and avoid light-colored clothing reflecting onto the panel during the run.

Place the probe properly

• Center of the screen, flat against the panel. Use the meter's counterweighted strap or a gentle tilt of the display so the sensor sits flush without pressure on the panel (especially on OLED).
• Let the meter itself warm up against the panel for a few minutes; some meters read dark levels differently when cold.
• Disable screen savers, sleep timers, and auto-brightness or ambient light sensors on the monitor itself for the duration of the run.

Use the right spectral correction

A three-filter colorimeter is only as accurate as the spectral correction matching the panel's emission spectra. KSF and PFS phosphor LCDs and QD-OLEDs are difficult cases for generic corrections: an uncorrected or mismatched filter set can push the measured white point in opposite directions on two panels read by the same meter, producing errors of many tint steps. Use the in-app corrections browser to fetch a matching .ccss, capture one with a spectrometer, or create a .ccmx from sequential reference and colorimeter readings. Gloam remembers the correction per monitor.

Know when to correct less

If a panel already measures close to target natively (roughly 2.5 dE average or better), full gamut correction has nothing real to fix, and verification will reliably come back worse. Use the white point correction only mode, which Gloam auto-suggests for OLED, or no correction at all. More correction is not more accuracy.

Verify in detail, then make visual matching explicit

Always read the detailed verification, not just the grade: the dE histograms and the worst-patch list tell you whether residual error is broadly distributed measurement noise or concentrated somewhere visible like the grayscale. On HDR displays, check the PQ tracking sweep to confirm absolute luminance tracking across the range.

Instruments and eyes can weigh display spectra differently (observer metamerism), so two displays may measure alike and still look different side by side. Use the report's White point tools or a small per-display Temperature/Tint trim when visual matching is the real goal. That trim changes the final rendered state; verify again if the report must describe the trimmed output.

Use Back freely

The calibration wizard is stateful. If you go back from Finalize Calibration, Gloam keeps the selected monitor, target, preset, correction file, display type, display mode, sound options, detailed verification choice, patch placement, and window size. This makes it safe to revise setup choices without losing the meter session.

Troubleshooting

Night Mode is not changing the display

Check the button state. Off disables all warmth, including the schedule. Auto only warms during the configured time window or sun-position window. Manual holds the selected temperature immediately.

Calibration will not start

Confirm the meter is connected, click Refresh, and read the setup warning. HDR targets require Windows HDR to be active on the selected display. SDR targets require HDR to be off. For correction files, .ccss and .ccmx files may contain negative samples; that is valid and expected.

The wrong monitor appears selected

Use the Identify button. The monitor identity popup appears near the upper-left of the selected display and fades out after a few seconds.

HDR refinement is unavailable

Open the live HDR report for the selected display and make sure its generated profile is both applied and enabled. Refinement requires the installed HDR tone LUTs, a connected meter, and the same display mode used by the report. Historical reports remain readable, but they cannot drive a new measurement loop.

A Game Lab profile does not activate

Confirm that the saved executable path still points to the game, that the profile is enabled, and that the game owns the foreground window. Re-scan the library if a launcher moved the installation. The active receipt is the authority: it shows the resolved game and every display currently covered by its window.

Verification says profile activation is suspect

Keep Windows in the SDR or HDR mode used for calibration, enable the generated profile, and run Verify again. The warning means the measured change did not resemble the expected installed correction closely enough; it is safer to fix the profile association or compositor state than to interpret the score as a valid calibrated result.

An update did not seem to install

Installed builds download updates in the background and apply them when the app exits or restarts. Portable builds do not auto-update. After installing an update, fully quit Gloam and launch it again.