darktable preset inspired by FujifilmNatura 1600

What the style changes

The style sets five darktable modules. It aims at an interpretation of Natura 1600: natural but lively color, soft skin without magenta, slightly green and raised shadows, moderate contrast and clear grain, as the datasheet and the reviews on the Fujifilm Natura 1600 film page describe them. All figures below come from renders made with darktable-cli 5.6.0 at 1000 px, measured in CIELab.

• Raised blacks, no change in contrast. The tone curve lifts the black point and keeps a gentle slope with a light shoulder. The darkest 5 % of photo 1014 rise from L 2.6 to 4.7, while global contrast stays put (Lsd 30.7 → 30.6; 14.3 → 14.8 on photo 0775). Shadows stay readable, and the rendering is softer than our Portra 800 style (blacks at L 3.0, contrast up by 1.5).
• Warm, natural skin. rgb primaries turns the reds slightly toward orange so skin does not go magenta. Skin hue moves from 44.2° to 49.7° and chroma from 16.4 to 19.2, about 17 % more, with no drift toward magenta.
• Lively colors, held back. The color equalizer raises red, yellow, blue and magenta a few percent, the “vibrant” colors and violets of the datasheet. Sky chroma rises from 27.5 to 28.8 (about 5 %) and the pink T-shirt from 33.7 to 37.6 (about 12 %). That stays below our Portra 800 style (about 20 % on the same shirt): neither Ektar nor pastel.
• A green cast in the shadows. A color balance rgb instance named “film” puts a faint green tint (130°) in the shadows and leaves the midtones and highlights almost neutral. Reviews disagree on this cast, so the tint is fixed and light.
• Marked grain, spread into the shadows. As a complementary measurement, on the sky of photo 0775 at 2560 px (standard deviation of the high-pass of L), the grain reaches 5.3, against 4.7 for our Portra 800 style, 3.4 for Superia X-TRA 400 and 2.8 for Portra 400. Of those four, it is the most visible in the collection.

What it leaves alone

• Your base development. The style contains no exposure, no sigmoid or filmic, no white balance and no LUT. Those settings stay as you made them.
• Your color balance rgb. The style’s color balance rgb is a separate instance named “film”: it is added next to yours, which stays untouched.
• But not your tone curve, rgb primaries, color equalizer or grain. When you apply a style from the lighttable or the darkroom, each of its modules replaces the instance of the same module with the same name, if the photo has one, and is added otherwise. The style’s tone curve, rgb primaries, color equalizer and grain carry no instance name, so they replace any settings you had already made in those four modules. Your earlier settings remain in the history.
• Your pipeline order. The style file carries no module order list, so it does not impose one on your image.

Exporting with a style, or rendering with darktable-cli, works differently: every module of the style is added as a separate instance. Our measurements were made that way, on darktable’s default rendering. The details are in Install and apply darktable styles.

Limits

• An interpretation, not a calibration. There is no Fujifilm datasheet titled Natura 1600: the bulletin we use is the one for Superia 1600, which reviews present as the same film, and it gives no grain figure that the style can follow. The tuning rests mostly on three reviews (Analog.cafe, Casual Photophile, Richard Haw).
• Grain set by ear. Its order of magnitude follows the reviews, not a measurement. A “fine grain” claim and an RMS of 4 quoted by one review sit awkwardly with grain that is more visible than in our Portra 800 style. The bulletin itself gives an RMS of 7.
• The green cast. The sources contradict each other, and the real cast depends on the exposure. The style applies one light, fixed tint. In the measurements the sea leans toward cyan by 7° (hue 270.1° → 262.9°), a stronger effect than intended. It is plausible given the green cast in the reviews.
• The fourth layer and the good behavior under fluorescent light are not simulated: they depend on the light of the scene.
• Export size matters. The grain is barely visible at 1000 px.

Tips

• Judge the grain at full size. Zoom to 100 % or export at your final size before you decide on the grain strength.
• Keep the shadows in check. If the green tint is too strong for your scene, lower the shadow chroma of the “film” color balance rgb instance, or the sea and other blues will lean cyan.
• Apply it early. If you plan to fine-tune the tone curve, rgb primaries, color equalizer or grain yourself, apply the style first: it would replace those settings if you made them before.
• Everything stays editable. Each module the style sets is an ordinary module instance: you can adjust it or switch it off afterwards.
• Installation: see Install and apply darktable styles.