darktable preset inspired by KodakT-Max 100

What the style changes

The style converts the photo to black and white the way T-Max 100 sees color, then adds a nearly straight tone curve and very fine grain. What it is based on is detailed on the Kodak T-Max 100 film page. All figures below come from renders made with darktable-cli 5.6.0 at 1000 px, measured in CIELab.

• Gray from the film’s spectral sensitivity. A color calibration instance named “N&B” mixes the channels with weights computed from Kodak’s published sensitivity curve, integrated against the CIE 1931 color matching functions. The weights lean much further to blue than T-Max 400 (0.3124 / 0.3533 / 0.3343) or Tri-X (0.3149 / 0.2994 / 0.3857).
  • Compared with a plain luminance conversion, and before any curve or grain, the sky gets lighter (L 55.2 → 59.2), the sea too (37.9 → 40.4) and a blue box as well (48.4 → 54.7), while skin (79.3 → 73.9) and a pink T-shirt (47.8 → 45.4) get darker. The direction is the same as Tri-X and T-Max 400, with a stronger effect: sky +4.0 (T-Max 400 +2.7, Tri-X +3.2), skin −5.4 (−3.0 and −3.8).
• Moderate contrast. The tone curve is nearly straight, with a midtone slope of about 1.15. Contrast rises from 14.3 to 16.4 on one test photo and from 30.7 to 32.0 on another, comparable to the T-Max 400 style: soft, not punchy.
• Open shadows. The shadow on the ground in one test photo lands at L 4.4 (base 7.6), as with T-Max 400, and 6.4 % of the pixels fall at or below 5/255 in that photo, against 16 % for the Tri-X style. Almost nothing clips in the highlights: 3 pixels at or above 250/255, against 13 for T-Max 400.
• Very fine grain. Grain is sized from the RMS granularity of 8. Its strength (19) is lower than in the T-Max 400 style (21), and the measured high-frequency noise on a sky at 1000 px is 0.8 times that of T-Max 400, following the ratio of the RMS values (8 to 10). At 2560 px it is 0.87 times.
• A truly neutral gray. Chroma falls from 8.6 to 0.0: no color cast is left.

What it leaves alone

• Your base development. The style contains no exposure, no sigmoid or filmic and no LUT. Those settings stay as you made them.

• But it switches off your main color calibration. The style contains two color calibration instances:

  • a disabled one with no instance name, which replaces your main color calibration and switches it off. It is set to “as shot in camera” with CAT16, like darktable’s default, so you can switch it back on;
  • the “N&B” instance, which is added and does the black-and-white conversion.

  Why: when an active color calibration runs after the black-and-white conversion, its chromatic adaptation tints the gray. darktable’s built-in black-and-white presets also bypass chromatic adaptation, and film does not white-balance either.

• It also replaces your tone curve and 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 and grain carry no instance name, so they replace any settings you had already made in those two modules. Your earlier settings remain in the history.

• Sharpness. The style does not sharpen edges: at 1000 or 2560 px, a digital sensor is already sharper than 35 mm film. The gap with T-Max 400 comes from grain and spectral sensitivity only.

The installation and export details are in Install and apply darktable styles.

Limits

• The spectral curve was read by eye. The style’s weights come from a reading of a thin line, at about ±0.05 log, and the start (400 nm) is the edge of the graph: nothing is published below 400 nm. The fall past 670 nm was assumed to continue at the slope read, with almost no weight in XYZ. The weights are sensitive to the reading in the blue: the effect on sky and skin is real, but its size is uncertain. A later, finer trace of the same graph, shown on the film page, stays within 0.12 log of the eye reading, with the largest differences in the steep drop past 650 nm.
• No independent numeric source on the spectral sensitivity: only Fstoppers points the same way as the datasheet (skies wash out), without any measurement.
• The tone curve was translated by hand, as for T-Max 400. It is not calibrated to densities and depends on the developer and the time. The style aims at a “D-76, normal time” rendering. The contrast difference with T-Max 400 is small: the datasheets do not clearly separate the two, except at the toe.
• Sharpness is not simulated (see above).
• The grain in darktable is procedural noise: it imitates the texture, not the flat shape of T-grains. The ratio with T-Max 400 (0.8 measured at 1000 px) follows the datasheet’s RMS values but remains an interpretation.
• Ektapan. The press presents the March 2026 return of the Ektapan name as a rename of the T-Max films. We found no confirmation from Kodak for T-Max 100. The style is built from the T-Max 100 datasheet.
• Color rendering is thinly documented. The other reviews we read talk about grain, sharpness and tonality and say little about color rendering.

Tips

• Apply it early. If you plan to fine-tune the tone curve or grain yourself, apply the style first: it would replace those settings if you made them before.
• See the spectral conversion alone by switching off the tone curve and grain modules the style set.
• Back to color: switch the main color calibration back on and switch off the “N&B” instance.
• Skies: the style already lightens blue skies. If you want them darker, lower the blue in the “N&B” instance, the digital equivalent of a yellow or orange filter.
• Installation: see Install and apply darktable styles.