Stellar scopes.
On any screen.

Install on your Mac

This release requires macOS 27 or later. You need DaVinci Resolve on a Mac, a recent web browser, and a shared local network. GTap is the Resolve effect that sends the picture to Galaxy Scopez. Nothing needs installing on your phone or tablet.

1. Download the latest Mac installer (.pkg). Quit DaVinci Resolve and stop any older Galaxy Scopez (formerly Ghetto Scopez) host before installing.
2. Double-click the installer. Follow the macOS Installer steps and enter your administrator password when asked.
3. Find GS in the menu bar. The installer includes GTap, the server and its runtime. A Galaxy Scopez alias with the app icon is added to your desktop. Double-click it to start the app and server; if the app is already running, it opens the GS menu with Start Server and Stop Server. The server starts after installation and at login. No Terminal, developer tools or separate Node.js installation is required.
4. Open Resolve and add GTap. Follow the connection steps below. Use GS → Open Viewer or Open User Guide on the Mac, and GTap’s network address on another display.

Use GS → Stop Server to stop serving scopes, and Start Server to start again. Quit Galaxy Scopez stops the server and closes the menu-bar app until you open it again or next log in. To reopen it, launch Galaxy Scopez from Applications. Show Log opens the server log.

The universal installer supports Apple silicon and Intel Macs. It is signed with Developer ID and notarised by Apple, with the notarisation ticket attached for offline verification. Allow local network access if macOS asks, otherwise this will not work.

Update or remove

To update, quit Resolve, stop the old host and run the new installer. Then reopen Resolve. Saved viewer settings stay in the browser when you use the same address.

To remove Galaxy Scopez, quit Resolve and choose GS → Quit Galaxy Scopez. Delete /Library/LaunchAgents/com.vidarandersen.ghettoscopez.plist, /Applications/Galaxy Scopez.app and /Library/OFX/Plugins/SignalLabTap.ofx.bundle, then log out and back in. macOS may ask for your administrator password.

Connect Resolve to your screen

1. Open Resolve and add GTap. On the Colour page, find GTap in the Effects library and add it to a serial node.
2. Put the node after the image conversion you want to measure. For display-referred scopes, place GTap after your output Colour Space Transform. Anything after GTap is not included. Resolve’s automatic colour-managed output transform can happen after the node graph.

   

3. Set GTap’s input colour space. For display-space readings, choose the BT.709 or BT.2020 primaries that match the RGB reaching the node. For readings before the display transform, choose Source / working-space RGB — no transform. GTap does not convert the image or change its appearance.
4. Open the viewer address. GTap’s panel shows the host status and scope address. Click Open this address in the GTap panel to open it in this Mac’s default browser, or copy the address into the browser on another device on the same network.
5. Tap Start listening. Open Controls to find it, or tap Fullscreen to start listening automatically. Play or scrub a clip if there is no picture yet.

Measure your working space

Place GTap at the point in your grade you want to measure, before the display transform. In GTap’s Input menu, choose Source / working-space RGB — no transform.

The scopes read the float32 RGB values supplied to GTap. Negative values and values above 1 are retained; widen the measurement level range in Settings to see them. RGB parade, histograms, DoubleD and the colour cube use these raw values.

The working-space notice identifies this mode. Waveform and tonal splits use weighted RGB with fixed BT.709 coefficients; vectors use the corresponding RGB differences. These are numerical views, not calibrated working-space luma or display chroma. Display targets and the skin-tone guide are hidden, and axes show float values. Preview and trace colours are raw visualisations without a display transform.

This option does not detect or convert your project’s primaries, gamma or log encoding. To measure a display conversion instead, put GTap after that conversion and choose the matching encoded BT.709 or BT.2020 option.

Make the viewer yours

Adjust the trace

Gain brings faint trace detail forward. Brightness changes how bright the trace looks. These controls change the display, not your grade. Colour and smoothing options let you choose the trace appearance.

Use pinch or the mouse wheel on supported plots to zoom. Use Reset to return to the starting view. Vectorscope magnification enlarges the trace while reference markings stay in place.

Detail Level changes trace detail independently of zoom. Cycle Q1–Q4 beside the zoom button in Controls, or choose Detail Level in Settings. Higher settings reveal finer detail but can be more demanding on your Mac and viewing device. Lowering Q does not crop the image.

Smooth softens trace detail in every scope. Histogram smoothing follows the value axis, hue smoothing wraps around the colour wheel, and the colour cube uses soft point edges. Scope measurements and source pixels remain unchanged.

The host indicator tells you whether the viewer is connected. The frame status tells you whether fresh data is arriving. A paused image can stay on screen while you compare or grade it.

The highlight and shadow boundaries can be adjusted in Settings.

Know what you’re looking at

Waveform

Shows levels from the left to the right of your image. Higher marks mean higher signal levels. Choose a plain trace, source colours or false colours by level.

For BT.2020 PQ footage, tap after the PQ output transform and choose BT.2020 primaries / encoded RGB in GTap. In Settings → Waveform, turn on PQ luminance (nits). This assumes the incoming signal is PQ, so leave it off for SDR, HLG and log footage. The waveform shows the luminance encoded in the signal on a scale that gives more room to darker values. For PAS highlight or shadow warnings, select an RGB scope or return to the encoded waveform.

RGB parade

Shows red, green and blue levels side by side. Compare the channels to spot colour casts and differences in their high and low levels.

RGB histogram

Shows how many pixels sit at each channel level. Choose overlaid channels, separate channels or a single colour channel.

Vectorscopes

Show colour direction and strength. Marks near the centre are less colourful; marks farther out are more colourful. Choose the full image, highlights, midtones, shadows or a combined highs/mids/lows strip. The outer hue ring shows chroma direction in degrees, with 0° on the positive Cb axis. It is on by default. Turn it off under Settings → Vectorscopes → Hue ring. This also hides the ring in PAS and OG Synth. It stays fixed when you zoom the trace and is hidden for raw working-space RGB. The 75% and 100% colour-bar target boxes cover ±5° in hue and ±5% in chroma amplitude around each reference.

DoubleD

Shows colour balance across image levels in two related plots. Choose a vertical or horizontal orientation. Colour guides remain visible even with a plain trace; the neutral axis is optional.

3D colour cube

Shows the spread of RGB colours in a cube. Drag with a mouse or finger to rotate it, pinch or scroll to zoom, and use Reset to restore the view.

Saturation vs luma

Shows colour strength from left to right and encoded luma from bottom to top. Use it to see whether stronger colours sit in darker or brighter parts of the image.

Hue histogram

Shows which hues are present and how strongly they contribute. Choose All colours, Near-neutral, Shadows or Highlights to look for subtle casts or compare colour across brightness ranges. Set up the hue histogram.

Parking assistance (PAS)

Tired of just talking about parking those levels all day long? Now you can actually park your grade like you park your car! Hear audible warnings when highlights, shadows or saturation approach your chosen limits. Turn PAS on in controls, toggle on and off in the active scope.

Isolate a color

Pick a colour from the source preview and narrow the range to see how it reads on the scopes. Set up colour isolation.

OG

Across a trillion blazing galaxies, the intergalactic Prince of the Universe and his neon tiger seek diamonds beyond counting. Empires tremble. Stars bow. Fabulous destiny awaits. Of course you always wanted to use the Resolve color grading tools as a game controller to play games - INSIDE OF RESOLVE - so here's the answer to what you've been yearning for all these years.

OG Synth (experimental)

Play a soaring synthesizer lead with Resolve’s colour controls or moving footage. Select OG Synth (experimental), start listening, then enable Sound in its header. Exposure controls pitch, saturation adds vibrato, and hue controls volume. A brightness histogram and vectorscope show both sides of the performance. Under Settings → OG Synth (experimental), adjust pitch range, glide, vibrato, master volume and filter tone. The synth is experimental; its sound and controls may change.

Select an area

Use an image region to measure one part of the picture. The rest of the image is left out of the scope readings.

1. Open Settings → Region and measurement.
2. Tap Capture source preview to capture the current image.
3. Drag a rectangle over the part you want to measure. You can also enter the start and end coordinates and tap Apply ROI.
4. Return to Scopes to see the measurements for your selection.
5. Tap Reset region when you want to measure the whole frame again.

Isolate a colour

Limit the scope readings to a colour or a range of similar colours.

1. Open Settings → Colour isolation.
2. Under Analyse, choose Selected colour or Skin hue range.
3. For a selected colour, tap Capture selection preview, then Pick colour from preview and tap the colour in the captured image.
4. Open Refine selection to adjust hue tolerance, saturation and luma limits.
5. Return to Scopes to measure the selected colours. Choose All colours to remove the filter.

The selection applies to all scopes, inside your chosen image region. Skin hue range selects colours, not faces; adjust it for your subject and lighting.

Inspect hues in shadows, highlights and near-greys

Add Hue histogram to a scope slot, then open Settings → Hue histogram. The scope heading shows the active preset, such as Hue histogram · Shadows. Its filters affect this histogram only; the other scopes keep their usual readings.

• All colours gives an overview of the image’s hues.
• Near-neutral brings out faint colour biases in almost-grey pixels.
• Shadows shows hues in darker parts of the picture.
• Highlights shows hues in brighter parts of the picture.

Adjust Saturation minimum/maximum and Brightness minimum/maximum to refine the range. The presets are starting points: log footage and a display-transformed image can need different brightness limits. Exactly grey pixels have no hue and are excluded.

Pixel count gives every included pixel equal weight. Chroma-weighted gives stronger colour differences more influence, reducing the prominence of tiny casts and noise. Hue readings become less stable very close to grey or black, so compare both views when inspecting subtle colour.

To see which parts of the image are included, use Capture source preview under Region and measurement while the hue histogram is displayed. Excluded pixels are dimmed. The preview is a visual aid; it may not show the faintest differences measured by the histogram. A selected image area and any global colour isolation also narrow the histogram’s input.

Hue presets, custom ranges and weighting are included in saved settings. These controls require GTap 1.2.27 or later.

Park your colours. Park your levels.

Parking assistance (PAS) adds sound to the scopes. Like a car’s parking sensors, it starts with slow pulses and speeds up as you approach a boundary. A continuous tone means you have reached it.

Turn on PAS in Controls. A square P appears in eligible scope headers. Tap one to choose the scope PAS follows; its P turns blue. Only one scope is assigned at a time. Tap the blue P to mute it, tap again to resume, or tap another scope’s P to move the assignment.

Choose what to listen for

Open Settings → Parking assist (PAS). Highlights and shadows are on by default. Enable Saturation separately. Each assist has its own pitch and volume, and their sounds can play together.

• Highlights: a high-pitched tone warns as bright values approach the upper boundary.
• Shadows: a low-pitched tone warns as dark values approach the lower boundary.
• Saturation: an undulating tone warns as colour strength approaches your chosen outer limit.

Set highlight and shadow boundaries

Drag the labelled lines in the waveform editor, or enter exact values. Start is where slow beeps begin; Continuous is where they become a steady tone. Moving the lines closer together makes the sound change more quickly over a smaller range. The up/down arrows adjust the gap between these boundaries.

Signal limits and Grading limits keep two separate sets of highlight and shadow boundaries. Use one for signal endpoints and the other for limits chosen for your grade. Choose values that suit the signal reaching GTap; nominal SDR black and white are not universal limits for log, HDR or working-space RGB.

Affected area (%) sets how much of the analysed image must reach a boundary before it influences the warning. Increase it to ignore isolated bright or dark pixels. Set it to 0% for single-pixel sensitivity.

WARNING: Black borders count as dark pixels: crop them in Resolve or select an image area that excludes them.

Monitor saturation

The inner circle marks the start of the warning; the outer circle marks the continuous tone. They measure distance from the grey centre of the vectorscope. This is signal chroma strength, not a perceptually uniform saturation percentage.

Saturation follows the whole image by default. Capturing a preview is optional; select an image area if you want to monitor only that part. On a shadows, midtones or highlights vectorscope, PAS follows that scope’s tonal band.

Fit limits to a hero frame

Pause on the frame you want to use as a starting point, then choose Fit limits to current image. This sets the highlight, shadow and saturation start boundaries from that image using your affected-area settings. It keeps the existing gaps to the continuous-tone boundaries. Review the result and adjust the limits for the shot.

PAS settings and the image-area selection are saved with your setup. Zoom, Q detail, Smooth, Gain and trace Brightness change how the trace looks; they do not change PAS thresholds. After loading the page, tap PAS in Controls if the browser needs permission to start sound. Stop listening or turn PAS off to silence all assists. PAS is suspended while OG is present and resumes when OG is removed.

Compare or match a grade

Keep a scope trace as a reference while you adjust the grade. The reference appears over the live trace so you can compare them.

1. With the image you want to remember on screen, tap Snap in that scope’s header.
2. Adjust your grade in Resolve. The live trace updates while the saved reference stays in place.
3. Tap A, B or C to show or hide each reference. They appear in red, green and blue.
4. Open Controls → Overlay to adjust opacity. The starting value is 25%.
5. Tap Clear in the scope header to remove its references. Use Clear all snapshots in Settings to remove every saved reference.

Each scope keeps three references. A fourth capture replaces the oldest. A reference with an incompatible range or colour space is hidden until the settings match.

References stay in that browser on that device and are separate from settings files. Clearing browser data can remove them.

Keep your preferred setup

The viewer remembers your settings in the current browser. Use Save settings to save a settings file, and Load settings to open one on another device. On phones and tablets, the browser may put saved files in Downloads; use the Files app or browser download menu to find them.

Reset to defaults restores the starting setup. Settings files do not include saved A/B/C scope references.

Quality changes the display resolution of the plots. Auto is a good starting point; lowering it can help a slower device. It does not change the chosen image region. Keep Debug off for normal use.

If something isn’t working

For a problem report, include your Mac and device models, OS and browser versions, Resolve version and what you were doing. Report an issue on GitHub.

Licence & credits

Galaxy Scopez and GTap are made by Vidar Andersen. Background · Source code

The project’s original code, documentation and supplied header artwork are offered under Creative Commons Attribution–NonCommercial–ShareAlike 4.0 International (CC BY-NC-SA 4.0), to the extent the author holds the rights. Credit Vidar Andersen, link the licence and state any changes. Commercial use is not permitted by this licence. Share adaptations under the same licence. See the full licence for the terms.

Third-party components keep their own licences:

• OpenFX support library — The Open Effects Association, BSD 3-Clause.
• NoSleep.js 0.12.0 — Rich Tibbett, MIT.
• ws 8.22.0 — its authors and contributors, MIT.
• Three.js 0.186.1 — its authors and contributors, MIT; included host dependency.
• zlib — Jean-loup Gailly and Mark Adler, zlib licence; supplied by macOS.

Read the full third-party notices. Node.js is bundled with the Mac application, under its own licence and notices. DaVinci Resolve (proprietary; licence supplied with the application), macOS (software licences) and Apple frameworks (developer terms) are separately licensed products; they are not included in this download. This project is not affiliated with or endorsed by Blackmagic Design or Apple.

The teaser’s glass button uses Amazing Glass by Ivan Tomac (MIT licence), adapted from the Lens Debaser header.