Developing a raw photo in LumiRaw, step by step

Before you start

You'll need a raw file: ARW, CR3 or CR2, NEF, RAF (X-Trans too), a DNG from a camera or a phone, and most other raw formats. A JPEG won't cut it: it's already been developed, and most of the good stuff a raw keeps is long gone. If your camera is newer than the decoder and the file refuses to open, run it through Adobe's free DNG Converter and open the DNG instead. The list of supported cameras tells you which models it knows.

Head to lumiraw.app and drop the file on the page, or tap the page on a phone to pick one. You can open several at once, or a whole folder: they line up in a strip along the bottom and get developed one at a time.

When a photo opens it has already had a first automatic pass: exposure, white balance, contrast and noise reduction, plus lens corrections if your lens is in the lensfun database. Sometimes that's enough; often it's just a starting point. If you only want the automatic version, tick Open photos straight at Download before opening the files. None of the steps is compulsory: Continue moves on, and Straight to download jumps to the end, leaving whatever you didn't touch on automatic.

Framing

First things first: a wonky horizon ruins everything. Straighten it with Tilt, sort out buildings that look like they're falling backwards with the two Shift sliders, and drag a box to crop, free or at a set ratio. If LumiRaw spots a crooked horizon or leaning verticals, it'll tell you and offer to fix them; your call. Remove empty corners trims to the biggest rectangle the tilt leaves clean.

Why crop first? Because every step after this one only looks at what you keep, so the exposure gets measured on the picture you'll actually show, not on the bits you're throwing away.

Your turn: Nudge Tilt until the picture sits straight, then drag a box on the photo to crop it. Go on, crop it tight.

Focus, for when it came out soft

This step only turns up when LumiRaw reckons the photo is out of focus, so you won't see it with our cat, who is pin sharp. It can undo some of the blur, but it's not magic: it won't bring back what was never there. Push How hard to pull until the detail comes back, and stop before the grain does. On a dark, noisy photo, best leave it alone.

Brightness

Too dark? Too bright? Draw a box over whatever matters most (a face, usually) and LumiRaw gets that bit right; the rest of the picture follows along. No box, and it measures the whole frame. Overall brightness moves everything at once, while Shadows, Midtones and Highlights each look after their own range of tones. Hover over one (or hold it on a phone) to see which parts of the photo it changes.

Your turn: Draw a box over the cat's face: that's where the exposure gets measured. Then play with Shadows and Highlights, and hover over one to see what it touches.

White balance

Everything looking a bit orange, or weirdly blue? Draw a box over something that ought to be neutral, like grey concrete, a white shirt or a sheet of paper, and steer clear of anything blown out. Temperature and Tint fine-tune it from there, and Clear takes you back to LumiRaw's own guess.

Your turn: Draw a box over something that should be white or grey (the white fur on the chest works a treat) and watch the colours settle down. Temperature and Tint fine-tune it.

Colour & detail

Vibrance lifts the dull colours first and keeps its hands off skin tones, so nobody ends up looking like a carrot. Clarity adds texture, or a soft glow if you turn it down; Dehaze cuts through haze; Noise reduction swaps grain for smoothness. Each slider starts wherever this photo was set automatically, so you're tweaking, not starting from scratch.

Your turn: Bump up Vibrance, then slide Clarity up for crunchy fur, and down for a dreamy glow.

Local

For when only part of the photo needs a hand:

• Graduated: drag from where the effect should be strongest to where it fades out. For a sky, start at the top.
• Radial: drag out from the centre. Tick Invert to change everything outside instead.
• Sky and Subject: masks LumiRaw finds for you. Subject spots people, animals and vehicles with a little network that runs right there in the tab.
• Heal: click a spot of dust and it's gone, patched from a similar area nearby.

Every filter gets its own exposure, temperature, saturation and softness.

Your turn: Pick Radial, drag out from the cat's face, tick Invert and lower its exposure: the background darkens and the face stays as it was.

Before / after

Drag the divider: Before is the file exactly as the camera recorded it. Underneath is every correction LumiRaw made on its own, and clicking one switches it off, so you can see what each one does, and keep only the ones you agree with. This is also where you pick the overall feel: Natural, Punchy for a scene that came out a bit limp, or Flat if you fancy doing your own colour later.

Your turn: Drag the divider to see the file as it came out of the camera (quite a difference). Click a correction in the list to switch it off, and again to bring it back.

Grade

Pick a look from RawTherapee's Film Simulation collection and set its Strength, draw your own curves, or load a .cube LUT if you've got a favourite. Toward grey, Darken the corners and Grain do the things a curve can't. The next photo you open keeps this grade, which helps when a set should look consistent.

Your turn: Try a few looks and play with their Strength. Then add a pinch of Grain and Darken the corners, for that film feel.

Download

Which format depends on what it's for:

For	Format	Why
Sending or posting	JPEG	Everything opens it. The default quality of 92 looks just like the original at a fraction of the size.
Editing further	16-bit PNG	Lossless and with every tone, so skies don't band when you keep editing it somewhere else.
Your own website	WebP	Lighter than a JPEG of the same quality.
Printing or archiving	TIFF or PNG	Lossless. The TIFF is 8-bit.

Under Long edge, Full resolution keeps every last pixel. For Instagram and friends, 1080 px is the size they show a landscape photo at anyway; upload a bigger one and they'll shrink it themselves, and not as nicely.

Heads up: the file keeps the camera's metadata, GPS position included if your camera saved one. If you took it at home, you might not want the whole internet knowing where that is.

Your turn: Pick a format and a size and hit Develop & download. Your browser develops the photo and saves it.

A whole batch at once

Got a strip of photos open? Mark the ones you want and hit Develop all N marked, as one zip. Each one is developed with its own tweaks, or with the current grade if you never got round to opening it.

Good to know

• The 100 % button shows the photo at full size, for checking focus and noise; double-click a spot to zoom straight there.
• Changed your mind? Undo and Redo are right there, and Ctrl+Z works too.
• Your tweaks are saved in the browser. Close the tab, open the same file again later, and everything is just how you left it.
• After the first visit it works offline, and there's a desktop version for Linux and Windows.
• A big raw needs a lot of memory, so an old phone may struggle with it.