SDR and HDR
HDR measurements retain highlights above SDR white where the capture path provides them. The choice applies to the desktop application as a whole.
SideScopes starts in SDR. Choose Dynamic Range → HDR in the desktop context menu or Settings to request extended-range capture and measurements. The choice persists across launches. Opening a scope, closing one, or loading a layout preset does not change it. The browser Lab is intentionally SDR-only.
Reading the scales
In HDR, Waveform, RGB Parade and Histogram use a fixed split scale. SDR levels from 0–100% occupy two thirds of the axis. The remaining third shows stops above SDR white:
| Level | Linear light relative to SDR white |
|---|---|
| 100% | SDR white |
| +1 stop | Twice white |
| +2 stops | Four times white |
| +3 stops | Eight times white |
| +4 stops | Sixteen times white |
The scale stays fixed as the region moves. Negative components and values beyond +4 remain at the edges, with their sampled pixel shares reported when present. Invalid measurements are excluded. The trace shows counts per bin, not density per equal linear-light interval.
Luma Waveform changes from encoded luma to linear luminance, labeled “Luminance”. RGB instruments map each original linear channel separately. Zones retains its 0–X tonal bands and adds separate highlight bands. Z opens Zones; it does not enable HDR.
If capture provides only SDR, the plots identify that limitation while keeping the selected HDR scale. They cannot reconstruct clipped highlights.
Color readings
The pointer readout and pinned samples retain signed, extended-range channel values where available. Their swatches and HEX values are SDR previews. Comparisons involving HDR use luminance differences in stops and RGB channel differences. They do not substitute a clipped SDR color-difference score for highlight brightness. On Mac, sampling outside the captured region remains SDR.
Vectorscope normalizes above-white linear RGB before encoding its chroma projection. This preserves a bright color’s direction instead of clipping it toward neutral. Use the other instruments to read its brightness.
Supported capture paths
On Apple Silicon with macOS 15 or later, HDR capture uses local-display Display P3 PQ. SideScopes validates the delivered encoding and decodes it with a nominal 100-nit SDR-white reference. This is an encoding reference, not a measurement of panel brightness. Older Mac capture paths remain SDR.
On Windows, HDR or Auto Color Management must supply floating-point scRGB frames. SideScopes uses the display’s current SDR content brightness as the white reference. Eight-bit fallback does not provide extended-range data. Unreadable brightness metadata triggers capture recovery before normalized values are published.
HDR adds capture, storage and analysis work. Smaller selected regions reduce that work. Keep application rendering and display settings consistent when comparing measurements: tone mapping and desktop composition can change the captured result. Very small excursions around white can be capture rounding.
These measurements describe rendered output, not camera exposure, recoverable RAW latitude or emitted panel brightness. See What SideScopes measures and the scope reference for that boundary.