No. A filter (or a LUT) applies a ready-made tint over an already-developed image: the same recipe, whatever the photo. neochrome works upstream, on the RAW file, and develops the colour from the light particular to each scene. It separates that light into three layers, lays transparent dyes we have designed onto them, and lets the colour be born of their superposition: the Kodachrome process, transposed to digital. Two different photos therefore don't receive the same layered-on treatment: each is developed according to its own light.

A preset and a LUT retouch colours that are already formed; neochrome makes them.

A preset is a set of saved settings — exposure, curves, colour shifts — laid as-is over your software's standard rendering: it bends the colours your demosaicing has already decided. A LUT is a fixed table that replaces an input colour with an output colour, always the same. In both cases the colour already exists, and the tool moves it.

neochrome moves nothing: it forms the colour upstream, by passing the light of the scene through three layers of transparent dye. Colour is born of an absorption — a layer that holds back light — and an intense tint becomes denser, deeper, instead of merely climbing in saturation the way a slider would push it. This substance, this stained-glass density, a stack of settings or a lookup table do not produce naturally. Likewise, the contour of the highlights and the hold of the shadows arise from the process itself, from one end of the image to the other, rather than being rebuilt setting by setting.

Not in the usual sense. neochrome does develop RAW files, but it isn't an editor like Lightroom, Capture One or darktable. Those programs are complete toolboxes, made to correct and retouch in every direction: cropping and straightening, lens defects, curves and tints reworked channel by channel, local brush retouching, dust removal, catalogue management.

neochrome, by contrast, is a RAW development engine. The simplest way to see what that is, is to think of the engine already inside your camera: when it produces a JPEG, that engine is what takes the sensor's raw light and makes a finished image of it — colours, contrast, the maker's own look. neochrome is an engine of that nature, but a separate one, written by us, and carrying its own rendering. So you don't open it to retouch an image, but to develop one: you load a RAW, and the few controls — light (exposure, temperature), modelling (contrast, density, curves), signature (reds, greens, grain) — only steer that development. Of cropping, lens correction, local retouching or a catalogue, there is none: it isn't a lack, it's the principle.

And this rendering isn't a stack of settings: it is conceived as an emulsion. Before digital, it was a film's emulsion — its layer of light-sensitive dyes — that gave an image its colour and its character; a camera's engine is, at bottom, only the digital heir to that role. neochrome belongs to this lineage: an engine whose character was composed in the manner of an emulsion — transparent dyes, the colour arising by absorption as the light passes through them. This is what digital emulsion means: not a retouching workshop, but a material, with a character of its own, through which your images develop.

The two therefore don't compete, they complement each other: crop, clean up or archive your images in your usual software, and go through neochrome for the development. And in every case, your original RAW file is never modified: neochrome reads it and forms a new image from it, without ever touching the original.

Neither, strictly speaking — and that is a deliberate choice.

Both words name the same ambition: to reproduce a look that already exists. A simulation analyses a real film — its curves, its measured dyes — and computes the most faithful imitation it can. The aim is resemblance to a measured object. neochrome does not do this: it surveys no film stock and seeks no match with a Kodachrome scan.

What it takes from Kodachrome and adapts is the process, not the result. The same architecture: light separated into three layers, transparent dyes superimposed, colour born of their crossing. But these dyes, we designed: chosen for their character and their harmony, not copied from a film. Kodachrome is our reference, our point of departure, not a model to be copied.

In other words, neochrome doesn't imitate Kodachrome: it inherits its gesture. It is an emulsion that never existed, built on the principle that made the beauty of the old one.

Yes, in its physical logic — and that is precisely where its rendering is decided.

A slide is a positive image viewed by transparency: a white light passes through it, layers of dye absorb part of it, and what comes out forms the colour. neochrome computes in exactly this way. It stacks three layers of transparent dye and passes a virtual white light through them; colour is born of what is absorbed, not of what is added. It is the working of a slide, rebuilt in computation.

This choice gives the rendering its substance. Because colour forms by absorption, an intense tint holds back more light and becomes denser, deeper, instead of merely gaining in brightness. This “stained-glass” density is precisely the signature of fine slides and of Kodachrome, which was itself a transparency film. So to sum up: neochrome has the logic of a slide, not its support: the result appears on screen, like any digital file, exactly as a real scanned Kodachrome is also viewed on screen.

Yes, as long as your camera produces RAW files.

neochrome starts from the raw file — the light measured by the sensor before any interpretation. It is this universal point of departure that makes it transposable: DSLR, mirrorless, advanced compact, even some smartphones — as long as they record in RAW, the camera will do. The process depends on no proprietary rendering, no brand, no sensor generation. It develops the light itself, wherever it comes from.

neochrome reads the common RAW formats (NEF, CR2/CR3, ARW, RAF, DNG, and others).

Because a JPEG is already developed, and developing is exactly what neochrome needs to do itself.

When your camera produces a JPEG, it has already interpreted the sensor's light: it chose the colours, the contrast, sharpened, smoothed, then threw away most of the data to keep only a finished image. To work from there would be to paint over an already-painted picture — exactly what a filter does, and what neochrome refuses to be.

The RAW, on the other hand, holds the light measured before any decision. It is this raw material that neochrome needs in order to separate the scene into three layers and form colour within them. Without it, the process would have nothing to develop: it could only retouch. Refusing the JPEG is therefore not a technical limitation, it is the very condition of the rendering: the guarantee that every image is truly developed, and not corrected.

neochrome is used directly online, in a simple interface: you load a RAW file, and you adjust a few settings to bring the image where you want it.

Because neochrome isn't a single button that would produce the same result for everyone. It is a development, and like any development it asks for a brief tuning — setting the exposure, the colour density, the balance of the tones, and, if you wish, the grain or the character of the dyes. Nothing technical: you move a slider, the image answers at once, and you stop when the rendering is right.

Your photos are never kept. The file you load is read and then erased at once; your image is then held only in memory, for the time of your session — so that you can develop as many versions of it as you like — and disappears as soon as you leave the engine. Nothing is stored, nothing is archived, nothing is reused.

Since the computation takes place online, your file passes through neochrome for the time it takes to be read; but it does not remain there, and your image lives only during your session. Your images stay yours, and yours alone. neochrome develops, it does not collect.

No. neochrome contains no AI, no trained model, no image generation.

A colourising AI invents: from an image, it guesses which colours would fit — a sky it supposes blue, a skin it supposes pink. The result may be beautiful, but it is imagined, and it can drift from what was really in front of the lens.

neochrome guesses nothing. Colour here is entirely governed by the light measured in your RAW file: each tint forms from what the sensor actually recorded, point by point. The process is physical and determinate: the same settings on the same file always give exactly the same result. What we chose are the dyes, their character; never the placement of the colours, which belongs to your scene.

In other words: neochrome does not reinvent your image, it develops it. The beauty of the rendering comes not from an invented colour, but from a real colour, set down by a process we have composed.

In a film, a dye is a material that absorbs part of the light passing through it — and it is this absorption that creates the colour. In neochrome, the dye is the transposition of that material into computation: not a tint, but a way of absorbing light, described precisely for each wavelength.

Each of our three dyes — cyan, magenta, yellow — is defined by how it stops or lets through each colour of the spectrum. This is where neochrome's signature lives. A dye never absorbs a single region of the light quite cleanly; it bites a little into the neighbouring ones. For two of them this spill is even intended — magenta bites into the blue, yellow into the green — while the cyan is kept pure. It is these choices that give the rendering its character rather than a cold neutrality. A dye, then, is not a colour laid onto the image. It is a virtual material that light passes through — and colour is born of that encounter.