Redlamp

Redlamp is a native, open-source RAW photo editor for Apple Silicon Macs, built from scratch in Swift and Metal. According to its website, it keeps "Lightroom's workflow" — the panels, slider names, ranges and keyboard shortcuts photographers already know — while rebuilding everything underneath as a native, GPU-first application. It describes itself as an editor, not a catalog: it opens folders of photos and keeps your edits in small sidecar files right next to them, and it never touches your originals. It runs on macOS 26, is currently at pre-alpha version 0.2.6, and the site states that the Mac editor comes first, with iPad and iPhone to follow from the same platform-neutral engine. The website explains the motivation behind the project directly: Lightroom defined how millions of photographers edit, but it is described as "a cross-platform application that doesn't feel at home on a Mac," and one that is tied to a subscription and a cloud. Redlamp's name comes from the darkroom safelight — "the one light you can work by without fogging the paper" — a way of saying you can see and shape your photo freely while the original is never harmed. Redlamp is licensed MPL-2.0, described as compatible with the App Store, and the site says its algorithms are implemented clean-room from published papers. It is free, with no subscription, and support is offered through Ko-fi. The Develop module is presented as "Lightroom's workflow, at home on the Mac." The site says the layout, panel order, slider names, ranges and defaults, and single-key shortcuts all carry over, so there is nothing to relearn, while everything underneath is rebuilt as a native, GPU-first app. Panels listed include Basic, Tone Curve, Color Mixer, Color Grading, Detail and Effects. The site states that Lightroom Classic's shortcuts are implemented as 83 actions on 87 key bindings, that you can find an adjustment (⌘F) by name or by the words people use, and that before and after is available in three layouts, cached so edits never re-render it. Sliders can be clicked to jump, dragged to adjust, Shift-dragged for fine control and double-clicked to reset; clicking the value lets you type one in or drag to scrub. Double-clicking a panel title resets it, and Option-clicking a header turns on Solo Mode. The histogram shows clipping indicators and you can drag across it to adjust Blacks, Shadows, Exposure, Highlights or Whites. The command palette is a central part of the workflow described on the site. ⌘K opens one search for every action, every Develop slider and every picker, and choosing a slider or a picker does not close the palette — it turns into that control, over the photo. ⌘F searches the sliders alone. Pressing Enter on a slider shrinks the palette to a slider bar over the photo; the arrow keys step the value, Shift moves ten times as far and Option moves finer, up and down move to the next slider, and a run of presses counts as one history step. Moving through a picker previews each choice on the photo, Enter applies it, and Esc goes back one level. You can also type a value directly, such as "exposure 0.7" or "temp 5600k", or type something like "x+0.3" in the slider bar. A hint bar always shows the keys that work right now. Responsiveness is framed as a core design principle. The site states that rendering and UI are strictly separated, so the UI never waits on the engine, the disk or the GPU. One fused Metal kernel applies every adjustment, frames arrive as IOSurfaces without a copy, and rendering never waits on the main thread. The site reports interactive renders at Fit in 0.6 to 3 ms on Apple Silicon, a full 26 MP frame at 1:1 in about 13 ms, a full-resolution export render in 45 ms, and opening a raw file in 70–250 ms, all measured on an Apple M1 Ultra with a Release build. Latest-wins scheduling collapses a burst of slider events to the newest, and a full mip pyramid means every zoom level samples the right resolution. Masking is described as "part of the architecture, not an afterthought." Every edit is a layer with its own adjustments plus a mask built from components that add, subtract and intersect, each of which can be inverted. Components include linear and radial gradients drawn directly on the photo, a brush with A and B brushes and Erase, Size, Feather, Flow, Density and Auto Mask plus pen pressure, and Luminance Range and Color Range selections that follow the photo's global edit. AI masks cover Subject, Background, People (including parts such as face skin, eyebrows, eye sclera, iris, lips, teeth and hair) and Sky using Apple Vision's built-in models, with nothing to download. Objects can be selected by hovering to preview and then clicking, dragging a box or brushing, using Segment Anything 2.1; Depth Range comes from a photo's own depth map or an estimated depth map; and Landscape masks cover water, vegetation, mountains, architecture, ground and snow. Mask presets such as Blue Sky, Brighten Subject, Darken Background, Smooth Skin, Whiten Teeth and Pop Eyes compute their masks for each photo. The site says masks are evaluated per pixel inside the same GPU kernel, so up to 16 of them cost well under a millisecond extra at Fit, and that every model runs on the Mac, with photos never uploaded. Colour handling is described as "serious colour science, scene-referred from the start." The pipeline is linear and scene-referred, with a camera white-balance model using Robertson's method and the camera's matrix. The Color Mixer works in OKLCh so hues move the way the eye expects, and some looks are measured against cameras' own renderings — the site notes that Standard v3 sits within ΔE 3.26 of the camera's Provia. Other colour tools include 3-way and individual colour-grading wheels with Blending and Balance, which also tint B&W images for split-toning, and parametric and point tone curves. Treatment switches between Colour and B&W, and Base Looks come with an Amount slider from 0 to 200 plus a browser that renders every look on the photo; six built-in looks and 15 film-style looks built on 3D look tables are listed. In the Detail panel, noise reduction is described as knowing your camera's noise. It scales to each photo's own noise, read from the DNG NoiseProfile tag, otherwise from the camera's calibrated profile at its ISO, otherwise measured from the raw data when the file opens. Luminance and Color controls are provided with Lightroom's controls, and luminance keeps fine texture through wavelet shrinkage and a non-local-means pass in exports. Sharpening is noise-aware: detail is measured on a denoised copy and applied to the untouched image, so grain passes through instead of being sharpened, and Detail moves from an unsharp mask towards Richardson–Lucy deconvolution. Texture, Clarity and Dehaze work globally and inside masks, and highlight reconstruction rebuilds clipped photosites. Recipes bring presets, profiles and LUTs into one open format. One format holds presets, profiles (a recipe's Base Look) and LUTs, and the site says you can type in a Fujifilm-style camera recipe card exactly as it is written. There are 39 bundled recipes in eight groups with hover to preview, import and export of .redrecipe, .cube, .3dl and HaldCLUT files, camera controls for Dynamic Range, Color Chrome and white-balance shift, and a Recipe Lab that checks every look across a 40-image set. Lightroom develop presets (.xmp) can also be imported, with a report of what came across exactly, approximately or not at all. Redlamp uses its own RAW pipeline. LibRaw only unpacks the file; black levels, white balance, demosaicing and colour all happen in Redlamp, on the GPU. The site lists Menon demosaic for Bayer sensors, Markesteijn's X-Trans demosaic, hot-pixel repair before demosaicing, row and column banding correction measured in the sensor's masked margins, and DNG gain maps applied before demosaicing. It states support for Sony ARW, Canon CR3, Nikon NEF, Fujifilm RAF, Apple ProRAW and Pixel DNG, plus JPEG, HEIC, TIFF and PNG. Edits are saved to a small sidecar next to each photo, and the original stays exactly as you shot it. Focus stacking is a separate Stack workspace. Redlamp spots a focus bracket in your folder and offers to merge it with a merge banner. Frames are stacked as demosaiced camera RGB before any edit, so every Develop slider still works on the result, and you can retouch from any frame. Stacks are detected for you, with Auto, Smooth and Detail strategies and a depth map, and the site reports that 25 Canon CR3 frames merge in about 8 seconds. A command-line tool, redlamp stack, does the same from the terminal. The workspace follows a Lightroom-style layout: Navigator, Folders, Recipes, Snapshots and History on the left, the photo with a filmstrip below in the centre, and the histogram, tool strip and Develop panels on the right. Folders are remembered by bookmark, shown as a tree with the number of photos in each, and nothing on disk is moved or changed — the filmstrip follows the disk by itself. The site says Redlamp is built to stay fast with any number of photos: a folder lists without reading a single sidecar, thumbnails decode in parallel on every core, memory is kept within a 128 MB budget and cached on disk in one file per folder, and the filmstrip is built so 50,000 photos cost what a screenful does. The benefits described are practical: photographers keep a workflow they already know, with the same panel layout, slider names and ranges and keyboard shortcuts, while gaining a native, GPU-first app where every slider lands within a frame and the UI never waits on the engine. Because edits are stored in sidecar files next to photos rather than in a catalog or the cloud, the described outcome is that you can see and shape your photo freely and the original is never harmed. On-device AI and optional downloadable models mean photos are never uploaded. Concrete scenarios where the product is used, as shown on the site, include editing RAW files from cameras such as a Sony α7R V, Nikon Z 6, Fujifilm X-T3 X-Trans, Canon EOS R6 and iPhone 12 Pro ProRAW; applying masks such as a linear gradient to darken and cool a sky while a feathered radial gradient warms trees; splitting tones with the colour-grading wheels; working at 1:1 with the Detail panel on a Canon EOS R6 CR3; applying camera-style recipes to Fujifilm raw files; and merging a focus bracket of 25 Canon CR3 frames into a single developing result. Redlamp is aimed at photographers who edit RAW files on a Mac and want the Lightroom workflow without a subscription or a cloud, and at users on Apple Silicon running macOS 26 — the site notes it is a pre-alpha release. It is free, with no subscription, and supported via Ko-fi, so it can also be downloaded and built from source under MPL-2.0. The technology stack listed is Swift and Metal, with an AppKit-based workspace, Apple Vision models and Core ML conversions running locally, all on one platform-neutral engine that the site says will also power iPad and iPhone versions. In short, Redlamp's stated proposition is Lightroom's workflow made native to the Mac: a from-scratch Swift and Metal RAW editor with a familiar Develop module, architecture-level masking, serious scene-referred colour, its own GPU-first RAW pipeline, and no subscription, no cloud and no changes to your originals.