darktable preset inspired by LomographyLomoChrome Metropolis

What the style changes

The style sets five darktable modules. Lomography publishes a Film Guide but no curves and no granularity, so the style is an interpretation of descriptions, summarized on the LomoChrome Metropolis film page. All figures below come from renders made with darktable-cli 5.6.0 at 1000 px, measured in CIELab. There is no reference render from another tool.

• Strong desaturation. A color balance rgb instance named “film” lowers saturation by 30 %, and color equalizer mutes yellows, blues, cyans and greens further. On photo 0775, global chroma goes from 21.4 to 7.3, about a third, and the sky from 27.5 to 9.1.
• Reds kept. Lomography says the film “loves red tones”. The pink T-shirt of photo 1014 keeps the most color: chroma drops by 16 % (33.7 → 28.2), against 60 to 70 % for the sky and the sea.
• A light green-yellow veil. The sea and sky move toward green-blue (sky hue 273.6° → 244.1°, sea 270.1° → 206.8°) and turn very dull. This follows the reviews that report a green cast. Others report a warm one; see Limits.
• Skin nearly intact. Skin chroma barely changes (16.4 → 15.6) and it gets a little more yellow (44.2° → 54.5°), in line with a review that finds skin “remarkably well-balanced”.
• Higher contrast, deeper blacks. The tone curve is a marked S. Contrast (Lsd) rises by 4.1 to 4.5 points on both test photos, and blacks deepen (L5 2.6 → 1.1 on photo 1014).
• Coarse grain. Coarseness 2400 and strength 35: stronger than the Portra 400 style (1200 / 14) and the LomoChrome Purple style (1600 / 22), for the “chunky” grain reviewers describe.
• Checked by eye: no strong cast and no posterization.

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 rgb primaries, color equalizer, tone curve 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. These four modules carry no instance name, so they replace any settings you had already made in them. 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

• No published curve or granularity. Contrast and grain are estimated from reviews.
• Contradictory color cast. Analog.cafe and Shoot It With Film report a green cast; Emulsive reports a yellow tint, almost sepia at ISO 400. The style leans toward a light green veil.
• Grain. The Film Guide says “fine” grain; the reviews say coarse. The style follows the reviews.
• One point on a moving target. On film, exposure changes the look: ISO 100 is closer to a regular negative, ISO 400 harder. The style fixes an intermediate look.
• Yellows are not measured by zones. They rely only on the visual color chart of the Film Guide: the test photos contain little saturated yellow.
• Deep shadows can clog. In photo 1013, the shadows are very dense and the arch is almost black. This is intended, but shadow detail is lost.

Tips

• The ISO effect is not built in. For a paler, more faded look, reduce the saturation cut of the “film” color balance rgb instance and lift the black end of the tone curve; for a harder look, do the opposite.
• Adjust the cast to your taste. If you prefer a warmer, sepia-leaning result, shift the shadows and midtones hue of the “film” instance toward orange.
• 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.
• Installation: see Install and apply darktable styles.