--- title: "Color tab: white balance, exposure and curves · Manual" description: "White balance, exposure, contrast and curves for your converted film scans: every control of the Color tab, and what it does to your photo." url: "https://open-negative-initiative.com/manual/color" date: "2026-11-03" --- [Manual](https://open-negative-initiative.com/manual) # Color **The colour and the light of your photo, in Open Negative Initiative.** A click for neutral light, then exposure, contrast and curves, block by block, as the Color tab lays them out. ![The editor on the Color tab: the AUTO WHITE BALANCE key over Temperature, Tint and Color density, then the Lighting block, beside a glass lift lit green on a Paris pavement at night.](https://open-negative-initiative.com/_astro/editor-color-negative.BPHj9Uhs_ZacVtI.webp) ## Color **Neutral light first, then your own colour.** Auto White Balance heads the block and writes Temperature and Tint. The block is hidden in B&W, and on the Scanner face its keypad stands in its place. - Auto White Balance **Neutral light in one click.** **Auto White Balance** reads the light of your frame and sets Temperature and Tint to match. - **Warmer or cooler.** Temperature runs from blue to yellow and reads +0 at rest. - **Greener or more magenta.** Tint moves the colour alone, never how light your photo is. ### The app's own note on Color > Auto White Balance reads the frame's light as it prints, its bright areas weighing more than a large warm subject, and corrects it with Temperature and Tint; the levels stay where the roll's measurement put them, and the Roll tab holds Balance strength, the share of that correction the two sliders take. Temperature and Tint move the colour alone and never how light the photograph is. Color density is the same control as saturation. ### Auto White Balance One click reads the light of your frame as it prints, its bright areas weighing more than a large warm subject, and sets Temperature and Tint so that light prints neutral. The roll's Balance strength, in the Roll tab, sets how much of the correction they take. - It runs only when you click it; the two sliders then retouch it like any value. - When the app does not yet know where to read, the key says **Crop before using the automatic balance**. - On several selected photos it asks: **Balance Each of the N**, each photo for itself, or **Average the N Balances**, one correction for a series shot in one light. - On a contact sheet, each frame is read through its own window and the mean is laid. - **Travels**: A preset can carry the key itself, as "Automatic WB (Temperature, Tint)": applying the preset measures each photo it lands on. What the key writes travels like any slider. - [Temperature and Tint](https://open-negative-initiative.com/manual/color#colour-filters) (Color) - [Balance Strength](https://open-negative-initiative.com/manual/roll#balance-strength) (Roll) - [Measuring Window](https://open-negative-initiative.com/manual/crop#measure-window) (Crop) - [One measurement per roll](https://open-negative-initiative.com/features/roll-measurement) (why it works, in Features) ### Temperature and Tint Temperature runs from blue to yellow, Tint from green to magenta. They move the colour of your photo alone, never how light it is, and Auto White Balance writes both. - A double click returns either to +0. - A colour you want only in the highlights or the shadows is a job for Curves. - **Temperature**: -100 to +100, at rest +0 - **Tint**: -100 to +100, at rest +0 - **Travels**: Copy Settings and Paste Settings carry it with the whole Color and Details tabs, and PASTE TO ROLL lays it on every photo of the roll; a preset carries it when its "Color (Temperature, Tint)" box is ticked. - [Auto White Balance](https://open-negative-initiative.com/manual/color#auto-white-balance) (Color) - [Color density](https://open-negative-initiative.com/manual/color#colour-density) (Color) ### Color density The same control as saturation, on your whole photo: to the right for more colour, to the left toward grey. The app labels it **Color density (same as saturation)**. - **Color density (same as saturation)**: -100 % to +100 %, at rest +0 % - **Travels**: Copy Settings and Paste Settings carry it with the whole Color and Details tabs, and PASTE TO ROLL lays it on every photo of the roll; a preset carries it when its "Color Density" box is ticked. - [Temperature and Tint](https://open-negative-initiative.com/manual/color#colour-filters) (Color) - [Chrome](https://open-negative-initiative.com/manual/color#effects-chrome) (Color) ## Paper Correction **Only when you proof on a paper profile.** Three gains laid last, against that paper alone: in any other working space they do nothing. - AUTO PAPER CORRECTION **Grey prints as grey on your paper.** **Auto Paper Correction** sets three gains from the paper's profile, never from your photo. - **Three gains, in EV.** Red, Green and Blue, ±0.50 EV each. The block shows only when you proof on a paper profile. ### The app's own note on Paper Correction > Gains laid last, on a color or a black and white print alike, against the paper the picture is proofed on, and on that paper alone: in any other working space they do nothing. Auto Paper Correction reads the paper's own white off its profile, never the picture, and sets the gains that print a grey as grey; the strongest stays at 0 so nothing clips. ### Paper Correction Only when your photo is proofed on a paper profile: three gains laid last, so a grey prints as grey on that paper. **AUTO PAPER CORRECTION** reads the paper's own white off its profile, never your photo. - In any other working space they do nothing. - The strongest gain stays at 0, so nothing clips. - **Red**: -0.50 EV to +0.50 EV, at rest +0.00 EV - **Green**: -0.50 EV to +0.50 EV, at rest +0.00 EV - **Blue**: -0.50 EV to +0.50 EV, at rest +0.00 EV - **Travels**: Copy Settings and Paste Settings carry it with the whole Color and Details tabs, and PASTE TO ROLL lays it on every photo of the roll; a preset carries it when its "Paper Correction" box is ticked. - [Custom: a paper's profile](https://open-negative-initiative.com/manual/export#export-profile) (Export) - [Temperature and Tint](https://open-negative-initiative.com/manual/color#colour-filters) (Color) - [Colour management](https://open-negative-initiative.com/features/colour-management) (why it works, in Features) ## Lighting **How light your photo is.** Every slider brightens to the right; Black point and White point move the ends of the scan itself. On the Scanner face, the keypad stands in its place. - **Brighter or darker, in EV.** A negative opens at +1.50 EV; a double click returns +0.00 EV. - **Open or deepen the shadows.** Shadows and Highlights each move one part of your tones, ±0.50. - **Set where black and white fall.** Black point and White point move the ends of your scan; every slider brightens to the right. ### The app's own note on Lighting > The negative back to light along a straight line: the black point on pure black, the white on pure white. Every slider brightens to the right; Black point and White point move the ends of the scan itself. ### Exposure How light your photo prints, in EV: a full stop in the shadows, while the highlights roll toward white instead of clipping. - A negative, colour or black and white, opens at +1.50 EV, because the roll's white is set near its brightest frames; a slide opens at +0.00 EV. - A double click returns +0.00 EV; the Lighting block's reset key returns the opening value. - **Exposure**: -4.00 EV to +4.00 EV, a double click returns +0.00 EV - **Travels**: Copy Settings and Paste Settings carry it with the whole Color and Details tabs, and PASTE TO ROLL lays it on every photo of the roll; a preset carries it when its "Lighting" box is ticked. - [Highlights and Shadows](https://open-negative-initiative.com/manual/color#lighting-shadows-highlights) (Color) - [White point and Black point](https://open-negative-initiative.com/manual/color#lighting-black-white) (Color) ### Highlights and Shadows Highlights raises or lowers the bright parts of your photo, Shadows the dark parts, each on its own. Like every Lighting slider, both brighten to the right. - **Highlights**: -0.50 to +0.50, at rest +0.00 - **Shadows**: -0.50 to +0.50, at rest +0.00 - **Travels**: Copy Settings and Paste Settings carry it with the whole Color and Details tabs, and PASTE TO ROLL lays it on every photo of the roll; a preset carries it when its "Lighting" box is ticked. - [Exposure](https://open-negative-initiative.com/manual/color#lighting-exposure) (Color) - [White point and Black point](https://open-negative-initiative.com/manual/color#lighting-black-white) (Color) ### White point and Black point White point and Black point move the ends of your scan itself. Black point's track runs the other way, so that right lifts the black, as every Lighting slider brightens to the right. - Each knob wears the colour it sets, white and black. - Both rest at 0: the roll's measurement already placed the ends. - **White point**: -33 % to +33 %, at rest +0 % - **Black point**: -20 % to +20 %, at rest +0 % - **Travels**: Copy Settings and Paste Settings carry it with the whole Color and Details tabs, and PASTE TO ROLL lays it on every photo of the roll; a preset carries it when its "Lighting" box is ticked. - [Per-Channel Levels](https://open-negative-initiative.com/manual/roll#per-channel-levels) (Roll) - [Contrast](https://open-negative-initiative.com/manual/color#effects-contrast) (Color) ## Effects **What is laid over the light.** Contrast and Vignette on every photo, Chrome on colour only. - **An S about a middle grey.** Contrast bends your photo's tones, its ends held. - **Corners, in stops.** Vignette darkens them up to 2 EV without shifting their colour; below zero it lightens them. - **Colour kept in the middle.** Chrome greys the ends of the tones, from 0 to 150%. Hidden in B&W. ### The app's own note on Effects > Contrast bends the print into an S about a middle grey, its ends held. Vignette darkens the corners in stops, without shifting their color; below zero it lightens them. Chrome lays a saturation curve over everything, greying the ends and keeping color in the middle. ### Contrast Bends your photo's tones into an S about a middle grey, its two ends held. - A preset carries it in its **Lighting** box, though the slider sits in Effects. - The Effects block's reset key returns it to +0.00; Lighting's leaves it. - **Contrast**: -0.50 to +0.50, at rest +0.00 - **Travels**: Copy Settings and Paste Settings carry it with the whole Color and Details tabs, and PASTE TO ROLL lays it on every photo of the roll; a preset carries it when its "Lighting" box is ticked. - [White point and Black point](https://open-negative-initiative.com/manual/color#lighting-black-white) (Color) - [Curves](https://open-negative-initiative.com/manual/color#curves-editor) (Color) ### Vignette Darkens the corners of your photo in stops, without shifting their colour; below zero it lightens them. - **Vignette**: -2.00 EV to +2.00 EV, at rest +0.00 EV - **Travels**: Copy Settings and Paste Settings carry it with the whole Color and Details tabs, and PASTE TO ROLL lays it on every photo of the roll; a preset carries it when its "Vignette" box is ticked. - [Contrast](https://open-negative-initiative.com/manual/color#effects-contrast) (Color) ### Chrome A fixed saturation curve over your whole photo: it greys the ends of the tones and keeps the colour in the middle. Off at 0%, and hidden in B&W. - **Chrome**: 0% to 150%, at rest 0% - **Travels**: Copy Settings and Paste Settings carry it with the whole Color and Details tabs, and PASTE TO ROLL lays it on every photo of the roll; a preset carries it when its "Chrome" box is ticked. - [Saturation Curve](https://open-negative-initiative.com/manual/color#saturation-curve) (Color) - [Color density](https://open-negative-initiative.com/manual/color#colour-density) (Color) ## Curves **Curves you draw yourself.** Five channels, folded until you open the block. ### The app's own note on Curves > Curves drawn by hand, one point at a time: a channel's own tints its highlights or its shadows alone. ### Curves Curves you draw on five channels: RGB, Luma, R, G and B. A colour channel's own curve tints your highlights or your shadows alone. - Press away from a point to add one, drag a point to move it, double-click a point to remove it. - A channel whose curve has moved is lit in the tabs. - The block opens folded. - **Travels**: Copy Settings and Paste Settings carry it with the whole Color and Details tabs, and PASTE TO ROLL lays it on every photo of the roll; a preset carries it when its "Curves" box is ticked. - [Contrast](https://open-negative-initiative.com/manual/color#effects-contrast) (Color) - [Temperature and Tint](https://open-negative-initiative.com/manual/color#colour-filters) (Color) ## Spectrogram Finishing **One colour range at a time.** Eight ranges on a wheel, folded until you open the block, and hidden in B&W. ### The app's own note on Spectrogram Finishing > Shifts one color range at a time without touching the others: turn a point around the wheel to move that color's hue, out or in to make it stronger or greyer. Click a point, then use the arrow keys. ### Spectrogram wheel Eight colour ranges on a wheel, from Red to Magenta. Turn a range's point around the wheel to move its hue, out or in to make it stronger or greyer; a second point on the same spoke sets its luminance. - Click a point, then use the arrow keys: left and right turn the hue, up and down move the point along its own axis. Tab walks to the next range clockwise. - A double click puts back that point's own values and no other. - The eight tabs under the wheel pick a range too, and light up the ranges you moved. - **Travels**: Copy Settings and Paste Settings carry it with the whole Color and Details tabs, and PASTE TO ROLL lays it on every photo of the roll; a preset carries it when its "Spectrogram Finishing" box is ticked. - [Hue, Saturation and Luminance](https://open-negative-initiative.com/manual/color#spectrogram-sliders) (Color) - [Saturation Curve](https://open-negative-initiative.com/manual/color#saturation-curve) (Color) ### Hue, Saturation and Luminance The chosen range's Hue, Saturation and Luminance as three sliders under the wheel, the same values its points show. - **Hue**: in degrees, at rest +0°; it stops 3° short of the neighbouring ranges' centres - **Saturation**: -100% to +100%, at rest +0% - **Luminance**: -100% to +100%, at rest +0% - **Travels**: Copy Settings and Paste Settings carry it with the whole Color and Details tabs, and PASTE TO ROLL lays it on every photo of the roll; a preset carries it when its "Spectrogram Finishing" box is ticked. - [Spectrogram wheel](https://open-negative-initiative.com/manual/color#spectrogram-wheel) (Color) ## Saturation Curve **Colour by light.** Five points from the black point to the white, folded until you open the block, and hidden in B&W. ### The app's own note on Saturation Curve > Saturation by light, from the black point to the white: raise a point to strengthen color in its tones, lower it toward grey. Drag a point along the light to choose its tones; double-click to return it to neutral. Brightness never moves. ### Saturation Curve Colour by light, from the black point to the white: raise a point to strengthen the colour in its tones, lower it toward grey. Your photo's brightness never moves. - Five points rest on a neutral line over your photo's histogram; drag one along the light to choose its tones. - Double-click a point to return it to neutral. - Chrome, in Effects, lays a fixed curve of the same kind. - **Travels**: Copy Settings and Paste Settings carry it with the whole Color and Details tabs, and PASTE TO ROLL lays it on every photo of the roll; a preset carries it when its "Saturation Curve" box is ticked. - [Chrome](https://open-negative-initiative.com/manual/color#effects-chrome) (Color) - [Color density](https://open-negative-initiative.com/manual/color#colour-density) (Color) ## The rest of the manual. **Every surface of the app, in the order of your work.** From the folder of scans to the exported file. - [Archive Opening the folder of your scans, your folders and favourites, the Archive and Projects tabs, a roll's own facts, the Rolls and Labels menus, and the ONI Trash.](https://open-negative-initiative.com/manual/archive) - [Prepare the Roll The five steps a roll goes through before its frames are edited: film, flat-field, film base, flags, measuring frame, then Measure.](https://open-negative-initiative.com/manual/prepare-the-roll) - [Roll What a roll shares: film type, flat-field, source encoding, the manual balance, the levels, dye separation and Balance strength.](https://open-negative-initiative.com/manual/roll) - [Crop The framing's own Copy and Paste, aspect ratio, straightening, quarter turns and mirrors, and the measuring window.](https://open-negative-initiative.com/manual/crop) - [Details Sharpening, chroma denoise and texture, the stages that act on the grain, judged in the loupe at full resolution.](https://open-negative-initiative.com/manual/details) - [De-dust The brush for dust and scratches, its size, and the list of corrections painted on the open photo.](https://open-negative-initiative.com/manual/de-dust) - [Scanner The Scanner face: ONI or Frontier, a lab scanner's keypad of D, C, M, Y and TEMP, and the finish laid after its render.](https://open-negative-initiative.com/manual/scanner) - [Presets The deck, saving a preset, its eighteen switches and white balance choice, the Settings menu, and Copy and Paste.](https://open-negative-initiative.com/manual/presets) - [Export The export screen: three presets, format, space and paper profiles, size, the HDR hack, each photo's EXIF line.](https://open-negative-initiative.com/manual/export) - [Toolbar and menus Every key of the bar and of the canvas margin, and every menu item with its shortcut.](https://open-negative-initiative.com/manual/toolbar) - [The whole manual Every surface on one page, in the order a roll goes through the app.](https://open-negative-initiative.com/manual) - [The guide Your first negative converted, step by step.](https://open-negative-initiative.com/guide) ## Convert your first roll tonight. **Add your folder, prepare the roll once, export.** Free, and nothing else to install. [Download for Mac](https://github.com/5e1y/open-negative-initiative-releases/releases/latest/download/OpenNegative.dmg) · [Download for Windows](https://github.com/5e1y/open-negative-initiative-releases/releases/latest/download/ONI-windows.zip) [How to convert a film negative, step by step](https://open-negative-initiative.com/guide) - **Mac**: macOS 13 or later on Apple Silicon or Intel - **Windows**: Windows 10 or 11 (64-bit) [Blocked at first launch?](https://open-negative-initiative.com/download#verify) ![A snowy Paris street at night, a lit cafe under arcades, tyre tracks in the snow.](https://open-negative-initiative.com/media/carousel/snow-night-1400.webp) ***Snow night.** Kodak Gold, converted in Open Negative Initiative.*