Android 4K HLG Video Recording Guide: Capturing 10-Bit HDR on Mobile

Capturing cinema-grade High Dynamic Range (HDR) on mobile hardware requires bypassing standard 8-bit pipeline bottlenecks and recording true 10-bit wide colour gamut video. This Android 4K HLG video recording guide provides the complete technical framework for shooting 10-bit HEVC footage using the Hybrid Log-Gamma (HLG) transfer function on supported mobile devices. By configuring the correct electro-optical transfer functions, locking exposure to standardized reflectance targets, and utilizing professional monitoring tools, mobile cinematographers can capture pristine master files that integrate directly into professional desktop post-production pipelines.

For filmmakers shooting on mobile devices, transitioning to an HDR capture pipeline transforms skin tone rendering, highlight roll-off, and color fidelity. Through tools like PrimeCam, Android filmmakers can finally leverage dedicated cinema camera controls tailored specifically for 10-bit HDR capture.

Demystifying Hybrid Log-Gamma: The Technical Core of Mobile HDR

Hybrid Log-Gamma (HLG) is an HDR standard jointly developed by the British Broadcasting Corporation (BBC) and the Japan Broadcasting Corporation (NHK), codified internationally in the ITU-R BT.2100 Recommendation. Unlike standard dynamic range (SDR) curves that map luminance strictly along a conventional gamma curve (such as ITU-R BT.709), HLG utilizes a hybrid electro-optical transfer function (EOTF). The lower half of the signal—covering deep shadows and midtones—follows a standard gamma curve, while the upper half applies a logarithmic curve to accommodate specular highlights up to 1,000 cd/m² (nits) or beyond without harsh digital clipping.

Capturing video within this transfer function requires moving beyond legacy 8-bit color depths. An 8-bit Rec. 709 recording allocates 256 discrete code values per color channel, yielding roughly 16.7 million potential color values. In contrast, 10-bit capture provides 1,024 code values per channel across the massive Rec. 2020 color space, resulting in over 1.07 billion distinct colors. The mathematical difference between these two capture depths represents an exponential increase in quantization precision:

• 8-Bit Rec. 709: 2 8 = 256 steps per channel → 256 × 256 × 256 = 16,777,216 color permutations. Gamut coverage is limited to roughly many the visible spectrum (CIE 1931).
• 10-Bit Rec. 2020: 2 10 = 1,024 steps per channel → 1,024 × 1,024 × 1,024 = 1,073,741,824 color permutations. Gamut coverage encompasses approximately many the visible spectrum.

When shooting with 10-bit HEVC Main 10 Android encoders, this quadrupled code density eliminates posterization and color banding in challenging gradients such as open skies, practical light falloffs, and delicate skin tones. Because the encoder distributes 1,024 quantization steps across the HLG curve, tonal gradations remain smooth even when dynamic range reaches 12 stops or higher.

HLG vs LOG for Mobile: Choosing the Right Curve for Android Sensors

When evaluating HLG vs LOG for mobile video production, cinematographers must consider how small mobile image sensors interact with mathematical transfer curves. Logarithmic curves (LOG) are scene-referred profiles designed to compress the entire sensor range linearly into a flat mathematical space. While LOG profiles are standard in digital cinema cameras with large 35mm sensors and massive photosites, they introduce significant technical trade-offs on mobile devices.

Mobile sensors feature microscopic pixel pitches that exhibit higher intrinsic noise floors. Applying an aggressive logarithmic transfer function lifts shadow values high into the midtone range, exposing underlying sensor thermal noise and fixed-pattern noise. When a LUT or manual grade pulls those shadows back down in post-production, the amplified noise floor frequently creates chroma artifacting. Furthermore, PrimeCam records HLG, not LOG. HLG is a display-referred curve that carries its own grade; there is no LOG profile.

Feature / Parameter	Hybrid Log-Gamma (HLG / BT.2100)	Logarithmic Profile (LOG)
Reference Type	Display-Referred (Direct HDR viewing)	Scene-Referred (Mathematical capture)
Color Gamut	Rec. 2020 Wide Gamut	Proprietary Wide Gamut / Variable
Mobile Sensor Noise Floor	Low (Shadows stay anchored in low code values)	Elevated (Shadows lifted, amplifying sensor noise)
On-Set Monitoring	WYSIWYG on HDR displays without viewing LUTs	Requires technical monitoring LUTs on set
Turnaround & Delivery	Instant delivery or flexible grading	Mandatory color transform pipeline

HLG provides an optimal balance for mobile sensors. Because the lower luminance values remain anchored to a gamma curve, shadow noise is naturally suppressed in the lowest code buckets rather than artificially stretched. Highlights roll off gracefully along the logarithmic shoulder, offering immediate HDR monitoring accuracy on modern OLED mobile displays without requiring preview LUTs or complex transform pipelines.

Hardware Requirements and Sensor Capabilities for 10-Bit Capture

Implementing 10-bit HLG recording requires modern hardware capabilities exposed through low-level camera architectures. The Android Camera2 API DynamicRangeProfiles documentation specifies explicit profile constants, notably DYNAMIC_RANGE_PROFILE_HLG10, which allow third-party capture software to request true 10-bit Rec. 2020 HLG data streams directly from the hardware Image Signal Processor (ISP).

Hardware compatibility varies significantly across manufacturers due to proprietary HAL (Hardware Abstraction Layer) implementations. PrimeCam has been tested on the Pixel 10 and nothing else, which makes every other handset untested rather than unsupported. It requires Android 13 or later and a camera that can record 4K in 10-bit HLG.

Beyond sensor and ISP processing, storage throughput is a vital hardware bottleneck. 4K 10-bit HEVC Main 10 encoding at high bitrates generates sustained data streams exceeding 100 to 150 Mbps. Handsets must utilize fast UFS 3.1 or UFS 4.0 internal flash storage to prevent buffer overruns and frame drops during extended takes. Read our production insights on the PrimeCam blog for deeper examinations of mobile storage performance during sustained high-bitrate video capture.

Step-by-Step Android 4K HLG Video Recording Guide: Exposure and Setup

To capture accurate, grading-ready HDR footage on Android, filmmakers must follow disciplined cinematic principles rather than relying on automatic computational exposure. Follow these steps to calibrate your capture settings.

1. Establish Frame Rate and Shutter Angle: Set your capture frame rate to a cinematic standard (such as 24 fps). To maintain natural motion blur, adhere to the 180-degree shutter rule by setting your manual shutter speed to 1/48s (or 1/50s in 50Hz lighting territories). PrimeCam targets 24 fps, and says so rather than assuming it. A take can come in marginally under nominal — auto exposure opening the shutter to the whole frame period leaves the sensor no time to read one out — so the app reports the rate it actually achieved in three places: the strip switches to the measured rate in warning colour while the take is rolling, the take card reads "23.92 fps measured, not 24.000", and the JSON sidecar carries measuredFps beside the requested fps. measuredFps is null when the take held its rate to within many and a number when it did not, so an editor conforming a timeline can tell the two cases apart.
2. Target Standardized Reference IRE Levels: Unlike SDR Rec. 709 where middle grey sits around many to many IRE and white clips abruptly at many IRE, HLG redistributes luminance values across a wider code range. many Middle Grey: Place middle grey test cards at exactly many IRE . many Diffuse White: Place clean matte white surfaces at many IRE . Specular Highlights: Allow chrome reflections, direct sun flares, and light sources to occupy the logarithmic shoulder between many and many IRE .
3. Lock Manual White Balance: rarely shoot HLG using auto white balance. Dynamic Kelvin shifts cross-contaminate 10-bit Rec. 2020 color matrices, making post-production color balance matching exceedingly difficult. Calibrate your white balance using a physical grey card and lock the Kelvin and tint values permanently for the duration of the scene.
4. Select Prime Lens Focal Equivalents: Choose your optical focal length purposefully. High-end multi-camera setups feature discrete optical sensors (such as a 13mm ultrawide, 24mm wide, and 104mm 5x telephoto). Avoid digital zoom steps between native lenses to preserve pixel-for-pixel 4K sensor readout and avoid digital interpolation artifacts.

Essential Exposure and Focus Tools for Precision 4K Capture

Precise 4K capture leaves zero margin for exposure or focus errors. Because HDR displays can reach extreme peak luminance, blown-out skin tones or missed focus are instantly noticeable on high-end screens.

Real-Time Luminance Waveforms and False Colour

Relying on mobile screen brightness under bright ambient sunlight is inherently unreliable. Professional monitoring tools translate raw sensor data into actionable exposure metrics:

• Real-Time Waveform Monitor: Displays the distribution of luminance across the entire frame from many to many IRE. Cinematographers can visually verify that shadow noise remains grounded near the many baseline while checking that diffuse skin tones do not creep above many IRE.
• Custom False Colour Overlays: False colour assigns discrete color values to specific IRE ranges. A calibrated false colour system highlights middle grey (many IRE) in green, diffuse white (many IRE) in yellow, and overexposed clipping (many+ IRE) in bright red. This ensures rapid, repeatable exposure calibration across diverse lighting setups.

Focus Peaking and Hardware-Assisted Subject Tracking

Acquiring critical focus at 4K resolution requires dedicated edge-detection peaking and responsive subject tracking algorithms. Focus peaking highlights high-contrast focal planes with vibrant colored outlines, allowing operators to manually pull focus smoothly across depth planes.

For dynamic moving shots, hardware-integrated autofocus pipelines ensure subjects remain pin-sharp without focus hunting. Subject detection runs on models bundled inside the app, not on a server, and names the rung it is holding — EYE, FACE, BODY, or NO SUBJECT.

PrimeCam focuses on the subject's nearer eye, and falls back to the head and then the body when it cannot resolve one — the ladder professional stills and cinema bodies use, and which was historically confined to them. It names the rung it is actually on: EYE, FACE, BODY, or NO SUBJECT. Faces and their eye positions come from the Pixel's own image signal processor; bodies, animal heads and eyes, and faces turned to profile come from models bundled in the app. Nothing leaves the device. Call it eye-detection autofocus or Eye AF, rarely "eye tracking" — it follows the subject's eye, not the operator's gaze.

Container Formats and NLE Workflow: Editing HLG Without Transcoding

A major friction point when shooting professional video on Android has historically been the output container format. Standard Android camera implementations package video into consumer MP4 containers that often omit standardized HDR metadata tags, causing non-linear editors (NLEs) like Apple Final Cut Pro to interpret the files incorrectly as blown-out Rec. 709 footage.

PrimeCam writes HEVC Main 10 in a QuickTime container with the hvc1 sample entry and a full Rec. 2020 HLG colour tag, which Final Cut Pro reads natively. This ensures that when clips are dropped into a Wide Gamut HDR (Rec. This point is context dependent and should be treated as a cautious recommendation.

PrimeCam does not record ProRes. It writes HEVC Main 10, which Final Cut Pro opens natively without transcoding. Capturing in HEVC Main 10 maintains high visual fidelity while keeping data rates light enough for real-time multi-stream timeline playback on modern hardware.

Additionally, each recorded take should generate an accompanying JSON metadata sidecar. This sidecar records critical technical parameters on a per-clip basis, including lens focal length, exposure duration, ISO gain, white balance Kelvin, and exact measured frame pacing. Post-production conforming engineers can parse these JSON sidecars to automate timeline conforming, lens distortion compensation, and shot logging.

Best Practices and Privacy in this Android 4K HLG Video Recording Guide

High-end digital film production requires software environments that respect operational security and data isolation. On active film sets, proprietary scripts, confidential storyboards, and unreleased commercial footage must remain strictly confined to local production storage. Technical standards such as the Apple Final Cut Pro HDR technical specifications emphasize data consistency and metadata integrity throughout the post-production lifecycle.

PrimeCam ships without the Android INTERNET permission, so the operating system itself refuses the app a network connection. There are no accounts, no analytics and no cloud sync. By removing the internet permission entirely from the application manifest, creators receive an absolute OS-enforced guarantee that no telemetry, metadata, or media streams can ever leave the local handset. For further architectural details on this security approach, review our PrimeCam privacy commitment.

A take is written as a spanned clip: numbered parts of a few seconds each, each one finished as it is written. If the app stops unexpectedly the last few seconds are lost rather than the whole take, and the parts carry the take's name and import as one clip. That is a floor on what a crash costs, not a promise that nothing is lost: PrimeCam 0.1.0 is an early build and nothing irreplaceable should be shot on it yet.

For independent filmmakers exploring this emerging mobile HDR capture workflow, PrimeCam 0.1.0 is on Google Play in open testing: anyone can install it from the listing without an invite. It is a test build, not a stable release. Regarding ongoing licensing and commercial plans, PrimeCam's price has not been announced.

Frequently Asked Questions

What is the difference between HLG and LOG when shooting video on Android?

HLG (Hybrid Log-Gamma) is a standardized display-referred HDR curve (BT.2100) that anchors shadow values along a conventional gamma curve while extending highlight headroom via a logarithmic shoulder. It allows direct monitoring on HDR displays without viewing LUTs. LOG is a scene-referred mathematical curve that compresses dynamic range evenly, which often lifts shadow noise floors on small mobile sensors and requires mandatory transform LUTs in post-production.

Why does 10-bit HEVC Main 10 matter compared to standard 8-bit video?

Standard 8-bit video provides 256 quantization levels per color channel (16.7 million total colors), which frequently causes noticeable banding in wide gradients and skies. 10-bit HEVC Main 10 provides 1,024 levels per channel (over 1.07 billion colors) across the wide Rec. 2020 color gamut, completely eliminating posterization and preserving smooth tonal gradations required for HDR mastering.

Can I edit Android 4K HLG footage directly in Final Cut Pro without transcoding?

Yes, provided the capture software packages the HEVC Main 10 stream into a QuickTime (.mov) container with the standard hvc1 sample entry and appropriate Rec. 2020 HLG color metadata tags. When properly tagged, Apple Final Cut Pro reads the files natively upon import without requiring intermediate ProRes transcoding or proxy generation.

What hardware is required to record 10-bit 4K HLG video on Android?

Capturing 10-bit HLG requires a handset running Android 13 or later whose camera hardware abstraction layer supports the DYNAMIC_RANGE_PROFILE_HLG10 constant via the Camera2 API, alongside an ISP capable of processing 10-bit 4K video pipelines and fast UFS 3.1 or UFS 4.0 internal storage.

Download the PrimeCam 0.1.0 open test build on Google Play to start capturing native 10-bit 4K HLG cinema footage directly on your Pixel 10.