Lightbox

Same 158 Sony ARW, same USB drive, cold	Bridge	Lightbox
Launch to a usable window	23.0 s	1.7 s
All 158 thumbnails on screen	10.9 s	0.82 s
Colour slider while dragging	blocked	23 ms
Export one file with a custom name	not possible	1 click
Paste a look onto 40 frames	4 clicks + 2 keys	2 keys
Works with no internet or licence	no	yes

Bridge numbers are measured, not quoted: a separate agent ran Bridge 2026 on the same folder with a cold cache and timed it against Bridge's own logs.

Something you should know: Bridge is broken on your Mac. It self-terminates 80 seconds after every launch, every time, with License Expired. Its log shows it cannot fetch an Adobe identity token, so a fixed 75-second timer expires and it quits. Camera Raw refuses to open at all: "Camera Raw editing is not enabled." Photoshop 2026 is signed in and fine, so your subscription is not the problem, it's Bridge's own token handshake. Worth knowing that the thing being replaced had already stopped working.

Folder open to full thumbnail grid	0.82 s
Colour slider drag	23 ms
Exposure / white balance drag	104 ms
1:1 zoom to check focus	154 ms
Full 24 MP export to JPEG	280 ms

Both apps read the JPEG preview already embedded in each RAW rather than demosaicing. That is the right trick and Bridge does it too; Lightbox is faster because it does not spend 5 seconds on a licence round-trip first.

Copy one look onto the whole shoot. Match a frame, select the rest, ⌘V. It pastes tone, colour, curve and detail but leaves each image's own crop alone, because the previous frame's crop is never what you want. ⌥⌘V lets you pick exactly which groups travel, and greys out the ones the copied frame never set. ⌘Z undoes the whole batch — that was the one irreversible thing in the app until it wasn't.

Blanket rename. ⇧⌘R, pick a pattern, see the first few results before committing. Sidecars follow their images. It renames in two passes, so shifting 001→002, 002→003 doesn't eat files the way a single pass does.

←→ next / previous   ⌘C⌘V copy / paste settings   ⌥⌘V paste some   \ hold for the original   Z 1:1   0-5 stars   6-9 labels   E export   GL grid / loupe   ⇧⌘R rename

• 22 functional checks pass: sidecar round-trip, blanket paste, export naming and counters, overlapping renames.
• Every tone slider was measured to move the image the direction its name says. Two didn't at first — Whites was inverted, and shadows were being applied twice (once by Apple's decoder, once by mine, which read as haze). Both fixed and re-measured.
• None of your originals were touched. No .ARW or .xmp on the drive was modified during any of this.

• No crop or straighten handle.the real gap The model, the render pipeline and the sidecar all carry a crop, so it survives a round-trip with Bridge — there's just nothing to drag yet. This is the first thing I'd add.
• No tone-curve editor. Curves are applied and read from sidecars, but have no UI.
• Dehaze approximates ACR rather than modelling haze. Rotated ACR crops import as their bounding box.
• Rebuilding the app resets the macOS folder grant, since the signature changes. One click on Open Folder fixes it.

~/Lightbox/dist/Lightbox-1.0.zip — 1.9 MB, self-contained, no Adobe and no dependencies. Your friends need the same right-click → Open on first launch. Source is at github.com/roninfaction/lightbox (private).

• The decoder was handing over pre-cooked pixels. Apple's RAW decoder applies its own tone curve and clips at 1.0 by default, so every slider was working on already-clipped data and highlight recovery genuinely did nothing. Measured: default decode tops out at 1.000, linear decode tops out at 2.697. That's 1.4 stops of headroom thrown away before the first adjustment.
• Tone was computed in too narrow a colour space, so a saturated pink left the gamut and each channel was clipped separately. That is exactly what turned the hoodie into a flat sticker: clipping per channel destroys the shading inside the colour.
• The curve was luminance-only, which keeps colour fully saturated as it gets brighter. Film and Camera Raw do the opposite, letting bright saturated colour fall toward white, and that falloff is what your eye reads as texture.

It now decodes linear and scene-referred, works in wide-gamut, and runs a filmic curve with a real shoulder as a single Metal kernel per pixel, compressing out-of-gamut colour instead of clipping it.

Camera Raw is the reference. A script drives Photoshop to render your RAWs through ACR, and those become ground truth to fit against.

Fitted	Result
Baseline exposure, against nine luminance percentiles on two frames that carry no sidecar, so ACR's own defaults are the target	RMS 0.0115
Sharpening, against measured edge acutance at 1:1 (was 63% of ACR)	100%
Saturation across four frames	within 0.033

	Before	Now
Colour slider drag	23 ms	17 ms
Exposure drag	104 ms	17 ms
Full 24 MP export	280 ms	330 ms

Exposure moved out of the decoder and into the kernel, where in linear light it is just a multiply. That means dragging it reuses the cached demosaic instead of re-decoding the RAW.

• Batch Rename's token model is better than mine. Ten token types, stackable rows, six sequence widths. Mine has nine tokens in one text field.
• Per-tile crop badges, which I can't show because there is still no crop tool.
• Dehaze, Clarity and Texture are approximations here, not ports of Adobe's algorithms. Noise reduction is Apple's. There is no lens-profile database.