iOS app

The production iOS app is a universal iPhone and iPad SwiftUI shell in ios/Runner/, with an Apple Watch companion in ios/OpenZCineWatch/. It consumes the portable Swift core in Sources/OpenZCineCore/ directly. Open ios/Runner.xcodeproj; the Simulator can run the demo session without a camera. See Setup.

Field Monitor interface

After connection, OpenZCine starts Nikon live view and opens the monitor when the first readable frame arrives. The monitor is one view tree for landscape and portrait. Rotation moves each module to its new place without rebuilding it. iPhone works in both landscape directions: the picture and controls swap sides so nothing hides behind the Dynamic Island.

DISP mode	What it shows
1 Live	Picture, capture strip, View Assist toolbar, status readouts and system rail
2 Clean	The picture only, plus camera fault and thermal or card warnings, the recording tally, the record control while rolling, and the DISP key
3 Command	A camera dashboard without the picture. Live view keeps running at the smallest frame so the timecode stays live.

Swipe the feed vertically to change DISP mode. Every monitor element is its own switch, per DISP mode and separately for video and photo, under Settings → Display. Clean view starts with the image, the rail, the focus box and the batteries; any View Assist tool can be pinned back on per tool. Some controls cannot be hidden from the inside: record returns while a take is rolling, Settings returns when no enabled DISP mode carries it, and the lock key returns whenever controls are locked.

The status deck shows timecode, REC state, codec, media, frame rate, battery, storage, temperature and camera warnings when the camera reports them. Timecode comes from the live-view frame header, so it is the camera’s own clock.

Use the trailing record control to start or stop in-camera recording. Record confirmation, haptics, keep-screen-awake and Bluetooth shutter or volume-button triggers are under Settings → Controls. Lock the interface to prevent accidental picker changes.

Pinch the live view to zoom anywhere in the frame; tap-to-focus follows the zoom. Fit shows the whole 16:9 picture; in portrait, pinch switches between fit and a center-cropped fill.

Anamorphic Desqueeze

Desqueeze scales the picture itself, not only the guides, in live view and playback. Presets include 1.6×, and a custom ratio runs from 1.00× to 2.00× in 0.01 steps. Photo mode has the same presets for live view, instant playback and the still viewer. It is display only: the camera original and any export are unchanged.

Vertical camera mode

Turn the body on its side and the picture follows, in video and photo, with a portrait layout built for it. Settings → Controls → Auto-Rotate Feed turns the upright rotation off. The recording is never affected.

Level

The level reads the camera’s own virtual-horizon angles from the live-view frame header. The core drops angles the camera reports as unreliable instead of drawing a guessed level.

Scopes and exposure assists

Tap an assist to toggle it; long-press it to open its configuration. The bar keeps your most used tools out and folds the rest behind its chevron.

• Waveform, RGB parade, histogram and vectorscope run live beside the picture. Waveform and parade brightness runs 0 to 200%.
• False color is codec-aware, zebras mark levels, and Traffic Lights is a RED-inspired per-channel meter that leans over or under from middle gray.
• In landscape and portrait fill, scope panels float and can be dragged and resized; positions persist. Portrait fit stacks the two most recently activated scopes. A third stays active but hidden until you close one or pinch to fill.
• In photo mode, scopes and false color read the stills preview (sRGB or HLG), and an EV meter follows the body’s exposure indicator.

Focus assists

• Focus peaking measures blur radius rather than edge contrast, so a defocused highlight no longer outranks sharp low-contrast detail. Sensitivity and color are adjustable.
• Tap-to-focus moves the camera’s AF area. AF and subject-detection boxes from the camera are drawn over the feed.
• The focus dial is an on-feed focus-by-wire pull in video and photo. It is off by default; turn it on in the FOCUS popup. A release keeps the dialed focus.

Framing and LUTs

Framing tools stack multiple aspect markers and masks, custom frames, thirds/phi/diagonal grids, a crosshair and the level. LUT preview applies built-in looks, downloaded RED LUTs or imported .cube files from 2³ to 64³. Press and hold a downloaded or imported LUT to remove it; built-in looks stay protected. RED LUTs are downloaded at runtime and never bundled.

Feed processing

Settings → Link → Processing offers a Feed Upscaler (Off, Fast, Quality, AI) and temporal Feed Noise Reduction. New installs start on Fast. AI infers detail the camera never captured, so judge critical focus on Quality or Fast. Link Health shows the rate the link is actually carrying.

Camera control

Tap a readout to open its picker. Pickers mirror the connected body: its values, in its order. ISO, shutter speed or angle, iris, white balance, exposure mode, focus mode, AF area and subject detection, drive, metering, image quality, picture control, resolution, frame rate and codec come from the camera’s own descriptors. A change counts once the camera reads it back.

• Auto ISO controls movie ISO auto for non-R3D codecs. R3D NE keeps its Low/High dual base and stays manual.
• H.265 shows 8-bit / 10-bit buttons beside the codec row only when the body advertises both depths.
• Camera clock sync sets a body that has drifted more than five seconds to the phone’s time on connect, never while recording.

Mode-dependent limits are listed under ZR exposure and focus.

Photography mode

Dedicated stills chrome with a real shutter (hold to burst in continuous drives, tap-to-AF, bulb and time), built-in and app self-timers, and pickers for mode (including U1 to U3 where the body has them), ISO Auto, focus, drive, white balance, size, quality (RAW plus JPEG or HEIF) and picture profile. Shots fired on the camera body appear in the app. Instant playback reviews the last shot with an optional focus point frozen at capture and a favorite star written to the card. Continuous-drive frames group into one burst stack.

Media and delivery

Open Media from the home screen or the monitor to browse the camera’s cards while clips cache progressively.

• Grid or list, thumbnail size, and filters derived from the tab you are on (container, resolution or JPEG/HEIF/NEF and L/M/S size, date, card slot).
• Play, scrub, jump 15 seconds, mute, zoom and pan, with scopes, markers and the selected LUT during review. A clean-view button hides everything but the picture.
• Slow-motion conform preview plays a high-frame-rate clip at the edit rate (for example 60 → 24 fps · 40%). The clip is never modified.
• Share and Save to Photos export MOV or MP4 and can bake the selected LUT. They work while the camera is connected.
• Frame.io upload (iOS 17.4 or newer, only in builds configured with credentials): sign in under Settings → Storage, choose or create a project, and upload. On camera Wi-Fi, the app can hop to the internet, deliver, then rejoin the camera.

Apple Watch

The watch mirrors the live feed with its LUT, camera status and timecode, and rolls or cuts recording. Photo mode adds a shutter and a shots-remaining readout; the crown magnifies the preview and a drag pans it.

USB-C and HDMI capture

USB-C tethering uses ImageCaptureCore: discovery, connection, reconnect on plug-in and after a loose cable, and a transport-aware first-pair wizard. On iPad, the picture can come from the camera’s HDMI output through a USB video capture device while exposure, focus, record and media stay on the camera link.

Share This Feed

Broadcast the monitor to other phones and iPads on set, with per-watcher assists and a control handoff. See Share This Feed.

Phone gyro logging

Rigidly mount this phone to the camera to record motion logs for Gyroflow. See Gyro logging for Gyroflow for mount calibration, foreground recording, sharing logs, and the Resolve workflow.

Device requirements

iOS and iPadOS 17.0 or newer; Frame.io needs 17.4. watchOS 10 or newer for the companion. Camera discovery needs Local Network access; the camera is used only to scan the Wi-Fi name and key from the camera screen, and on iPad to read a USB capture device. Photos access is requested only for Save to Photos.

The Simulator cannot reach a camera. Protocol tests (just test) do not need hardware. Wire notes for iOS: iOS protocol notes.

Releases

Public beta: TestFlight. A merge to main that changes native iOS code uploads a TestFlight build. Pull requests that change Sources/, Tests/, ios/, Package.swift, scripts/ or the justfile must replace ios/TestFlight/WhatToTest.en-US.txt with plain-language tester notes; CI rejects stale or developer-centric copy. Maintainer setup: docs/testflight-ci.md. Release window: 0.2.5.

If something fails, use Operator Setup → System → Report a Problem or Settings → Share Diagnostics (Troubleshooting).