Picture Controls and Colour

Picture one frame of a kingfisher on a grey morning, developed three ways inside the camera. Under Standard the orange breast glows against the water. Under Flat it is quieter and the shadow under the bank keeps more detail. Under Monochrome the orange is gone. The sensor recorded the same numbers each time. The recipe applied afterwards differs, and Nikon calls that recipe a Picture Control.

Nineteen menu items shape the recipe, ten in the photo shooting menu and nine in the video recording menu. White balance has its own chapter, White Balance, and the choice between JPEG, HEIF and raw lives in RAW, JPEG, HEIF and Tone Mode.

01.From Raw Numbers to a Finished Picture

Why Raw Data Needs a Curve

The Z6III records raw NEF files at 14 bits (p. 998), so each pixel can take $2^{14} = 16{,}384$ values. The sensor is linear: twice the light gives twice the number. The brightest stop, from half the maximum light up to the maximum, therefore uses the values 8,192 to 16,383, half of every level available. The next stop down gets 4,096 and the one after it 2,048. If $n$ counts stops down from the top, with $n = 1$ for the brightest, that stop holds

$$\text{levels}(n) = 2^{14-n},$$

which leaves 64 levels for $n = 8$. A JPEG stores 8 bits per colour channel, only $2^8 = 256$ values. Dividing every raw value by 64 would squeeze that whole eighth stop onto a single JPEG value. So the camera bends the scale, giving dark tones more output values than their share of the light. That bend is a tone curve.

The web's default bend comes from the sRGB standard. Write $L$ for linear brightness from 0 (black) to 1 (the brightest value) and $V$ for the encoded value on the same scale. Mid grey reflects 18% of the light, so $L = 0.18$. Raise it to the power $1/2.4$ to get 0.489, multiply by 1.055 and subtract 0.055, and you reach $V = 0.461$, about 118 on the 0 to 255 scale. That is close to halfway up, although mid grey carries under a fifth of the light. For all but the darkest values,

$$V = 1.055\,L^{1/2.4} - 0.055.$$

What a Picture Control Adds

A Picture Control reshapes that bend and adds colour and sharpening. Nikon presents the system as a set of processing settings, among them sharpening, contrast, brightness, saturation and hue, that its cameras and software can share (p. 181).

Contrast is the steepness of the tone curve through the midtones. A steeper middle pushes neighbouring greys apart and pays for it at the ends. In the figure, six stops below the brightest value the steep curve gives about 23 and the gentle one about 42. Nikon does not publish its curves, so these shapes are drawn for illustration. Brightness moves the midtones alone and leaves highlights and shadows in place (p. 187).

Saturation is distance from grey. Take a skin-tone pixel with red, green and blue values of 180, 120 and 90, whose average, 130, is a grey of roughly the same brightness. A factor of 1.2 moves each channel 20% further from that grey, giving 190, 118 and 82. With $g$ the grey, $c$ a channel value and $s$ the factor,

$$c' = g + s\,(c - g).$$

This shows the principle, not Nikon's unpublished method. Hue works differently: it turns colours around the colour wheel, so a red drifts towards orange or magenta without losing vividness.

Sharpening exaggerates edges. A row of pixels across a feather's edge reads 100, 100, 100, 150, 150, 150. Darken the pixel before the jump and brighten the one after, and it reads 100, 100, 90, 160, 150, 150. The jump grows from 50 to 70 and looks crisper. The Z6III does this at three scales. Sharpening handles small detail, Clarity handles large areas without touching fine outlines or overall brightness and contrast, and Mid-range sharpening sits between them (p. 187). Quick sharp moves all three together. Each Picture Control sets these dials differently, which is why one frame looks different in each.

02.Choosing a Picture Control

Set Picture Control appears in both shooting menus and in the default i menus (pp. 83-84, 183), and a custom control can take it too (pp. 712, 755). With Custom Setting d10 View mode (photo Lv) on Show effects of settings, the shooting display previews the Picture Control (p. 673). Adjust for ease of viewing hides it, unless its Custom option leaves Set Picture Control on Preview current setting (p. 674). In video mode the effects always show (p. 673). The photo default is Auto (p. 447).

Custom Picture Controls C-1 to C-9 and any Cloud Picture Controls appear below these (p. 184).

The Creative Picture Controls

The twenty Creative Picture Controls, k01 to k20, are finished looks built from hue, tone and saturation (pp. 181, 184). In alphabetical order their names are Binary, Bleached, Blue, Carbon, Charcoal, Denim, Dramatic, Dream, Graphite, Melancholic, Morning, Pink, Pop, Pure, Red, Sepia, Silence, Somber, Sunday and Toy (p. 999). Only they have Effect level, which scales the whole look, and some offer Toning (pp. 187-188). I keep them for casual JPEGs.

Adjusting a Picture Control

Highlight a Picture Control and press right. Up and down choose a parameter, left and right change it by 1, and the sub-command dial changes it by 0.25. O resets, J saves, and an asterisk marks the result as modified (p. 186). From the i menu the same sliders sit over a live view, which is the better way to judge them (p. 190).

Not every parameter appears everywhere (pp. 187-188). Brightness is missing from Auto, the Creative looks and HLG, the tone mode meant for high dynamic range displays that a later section covers. Saturation is missing from the three monochromes and some Creative looks, and Hue from those plus Auto. Filter effects and Toning appear only for the monochromes and some Creative looks. Highlights and Shadows exist only for HLG.

Quick sharp, Contrast and Saturation can be set to A, which lets the camera decide frame by frame from exposure and subject position (pp. 189, 916). Nikon's troubleshooting pages name A, the Auto Picture Control and any Custom Picture Control based on Auto as reasons results vary between pictures, and advise fixed values for a series (p. 916). Auto's own adjustment runs from A−2 to A+2 (p. 189). The RG gives no other numeric ranges, so I quote none.

Black and White Filters and Toning

A red filter on a film camera passes red light and blocks much of the blue, so a blue sky records darker while white clouds stay bright. Filter effects imitates this in processing. Y, O and R raise contrast and darken skies, in rising strength, and G softens skin tones (p. 189). Deep Tone Monochrome carries a strong red filter of its own. Choosing a filter replaces it, so Y, O or R there lower its contrast (p. 189). Toning tints the grey with one of nine choices, cyanotype and sepia among them, and each except B&W has its own saturation (p. 188).

Picture Controls for HLG Photos

With the photo tone mode on HLG, the camera saves HEIF files with a wider dynamic range and uses this item instead (pp. 462-463). It offers Standard, the default, Monochrome and Flat (pp. 185, 447), and swaps Brightness for Highlights and Shadows (p. 187). Colour space is locked to BT.2100, the colour standard for high dynamic range television, and Active D-Lighting is unavailable (p. 462).

03.Saving and Sharing Picture Controls

Manage Picture Control

Manage Picture Control, in either shooting menu (pp. 470, 591), saves an adjusted Picture Control as a Custom Picture Control in one of nine places, C-1 to C-9. Save/edit starts from any Picture Control and uses the adjustment screen above. The proposed name is the original's plus a two-digit number, and you can type up to nineteen characters instead. Rename and Delete do what they say. Load/save has Copy to camera, Delete from card and Copy to card, which exports into 99 numbered places in NIKON/CUSTOMPC (pp. 191-194). A Custom Picture Control keeps its base's parameter list (p. 193).

Load/save sees only the card in the primary slot (p. 194), which Card Slots and File Handling explains. Copy to camera finds files only in the card's root folder or in NIKON/CUSTOMPC (p. 194). NX Studio, Nikon's free software (p. 463), can build Custom Picture Controls with its Flexible Color tools. The camera imports those but cannot adjust or rename them (p. 194).

Cloud Picture Controls and Imaging Recipes

Nikon Imaging Cloud, at imagingcloud.nikon.com, transfers images, updates firmware, keeps imaging recipes of shooting data, your own or public ones, and supplies Picture Controls (p. 31). Picture Controls arrive over Wi-Fi once the network menu item Nikon Imaging Cloud has its Connect to Nikon Imaging Cloud option at ON and camera sign-in is enabled on the cloud side (p. 195). Pressing MENU may then offer to register them. Yes registers them, so they join the choices under Set Picture Control. No leaves notification marks and keeps manual import open through the Add Cloud Picture Control files item, found under Set Picture Control (pp. 196, 469). To adjust one, add it through Manage Picture Control, which makes it a Custom Picture Control (pp. 182, 195).

Nikon USA's Imaging Cloud page says a camera can take up to nine Cloud Picture Control presets, and describes an Imaging Recipe as a package of a story, suggested camera settings and Cloud Picture Control presets to download. The limit is stated for the service in general rather than for the Z6III alone, though the page lists the Z6III among compatible cameras.

04.What a Picture Control Does to a Raw File

A Picture Control never changes the raw numbers in a NEF. The camera records which one was used, and playback shows it (pp. 229, 234). Nikon calls NEF processing the stage where Picture Control, white balance and exposure compensation can still change freely (p. 118).

Nikon's tools apply it. RAW processing, under Retouch in the playback i menu, makes a JPEG from a NEF and lets you revisit, among others, Picture Control, Vignette control, Color space, High ISO NR, Portrait impression balance, Diffraction compensation and Active D-Lighting (p. 265). Skin softening and Auto distortion control are not on that list. Nikon warns that hues may still differ from a JPEG shot directly (p. 261). For an HLG raw photo, the HEIF copy keeps BT.2100 and Active D-Lighting cannot be adjusted (p. 270).

Other software does not show it. For NEF files, only Nikon software such as NX Studio shows what Set Picture Control, Active D-Lighting, Vignette control and Set Picture Control (HLG) did (p. 919). Another raw converter opens the file with its own rendering.

It still shapes the viewfinder through d10 (p. 673), so set one deliberately even for raw.

05.Colour Space: sRGB and Adobe RGB

A screen mixes every colour from three lights, a red, a green and a blue, and no mix can be purer than its purest ingredient. Colour scientists map colours by two numbers, $x$ and $y$, called chromaticity, which capture hue and purity but not brightness. Every visible colour falls in a horseshoe on that map, defined in 1931 by the CIE, the international lighting commission. Three primaries mark a triangle inside it, and that triangle is the gamut. A colour space is the triangle plus a white point, which fixes what equal red, green and blue look like, and a tone curve.

Only green differs. Adobe's sits further out towards saturated greens and cyans, so its triangle is bigger, and that has two costs. The same numbers mean different colours: red 0, green 255, blue 0 is a purer green in Adobe RGB, and software that ignores the file's space usually assumes sRGB and shows an Adobe RGB picture duller than it should. And 8 bits still give 256 values per channel, so stretching them over a larger triangle makes each step coarser. Adobe RGB also uses a plain power curve with exponent $563/256 \approx 2.2$.

Nikon advises sRGB, the default, for general printing and display, and Adobe RGB for professional publication and commercial printing. It adds that Adobe RGB needs colour-managed applications, displays and printers, and that third-party software may override the camera's choice while NX Studio keeps it (p. 472). I use sRGB for every genre, because my JPEGs end on screens. For raw files it can be changed later (p. 265).

Video has no Color space item. With H.265 or H.264 files, SDR (standard dynamic range) video records in BT.709, the colour standard of ordinary high-definition video, HLG in BT.2100, and N-Log, Nikon's flat recording meant for grading afterwards, in BT.2020, a wider ultra-high-definition standard (p. 199), and the video part of this guide covers HLG and N-Log.

06.Active D-Lighting

Shoot a sunlit garden from a dark room and either the garden goes white or the room goes black. Active D-Lighting tries to keep detail at both ends while contrast still looks natural, and it works best with matrix metering (p. 473), covered in Metering. The photo options run from Off, the default, through Low, Normal, High and Extra high, plus Auto, and the video version drops Auto (pp. 473, 593).

Nikon's cautions are specific (p. 474). It can add noise as bright specks, fog or lines, and it can leave uneven shading. Auto acts as Normal in mode M, which Exposure Modes covers. It has no effect at Hi 0.3 to Hi 1.7, even when auto ISO picks them, as ISO and Auto ISO explains. It is unavailable for HLG photos (p. 462), fixed at Off for HLG video (p. 215), and unavailable with N-Log and raw video (pp. 214, 216).

Nikon does not explain how it works, so I will not guess. For raw files I keep it Off, since NX Studio or in-camera processing can apply it later (pp. 265, 919). Any fixed level keeps the frames of a burst alike, and only Auto chooses afresh for each scene. For JPEG-only work in harsh contrast I use Low. For video, Off.

07.Noise Reduction for Video

High ISO NR in the video menu smooths the speckle that grows with ISO and works like the photo item that ISO and Auto ISO covers (p. 594). High, Normal and Low act at every ISO, harder as ISO rises, and Off still applies a little where needed (p. 476). The default, Normal (p. 578), is where I leave it for gimbal footage. N-Log and raw video disable it (pp. 214, 216).

08.Lens Corrections

Vignette control, Diffraction compensation and Auto distortion control are shared, so a change in either menu applies to both (pp. 477-479, 595-597).

Vignette Control

Vignetting is darkening towards the corners, strongest wide open. Vignette control brightens the edges by an amount that depends on the lens, at High, Normal (the default), Low or Off (pp. 447, 477). Brightening a corner raises its noise along with its signal, so a corrected corner stays noisier than the centre. Nikon's own cautions are that JPEG edges can show fog or uneven brightness and that custom or modified Picture Controls may not give the intended result, so test first (p. 477). I keep Normal, since for raw files it can be changed later (p. 265).

Diffraction Compensation

Light through a small aperture spreads, so a point becomes a small disc that grows as the aperture shrinks. For green light of wavelength $\lambda = 0.55$ micrometres at f/16, the disc measures about $2.44 \times 0.55 \times 16 \approx 21.5$ micrometres across to its first dark ring. The sensor is 35.9 mm wide with 6,048 pixels across (pp. 997-998), so a pixel is about 5.94 micrometres and the disc covers about 3.6 pixels. At f/8 it covers about 1.8. With $N$ the f-number,

$$d \approx 2.44\,\lambda\,N.$$

ON, the default, reduces this softening at small apertures (pp. 447, 478), by a method Nikon does not describe. I leave it on, and for raw files it can be changed later (p. 265). Raw video disables it (p. 214).

Auto Distortion Control

Barrel distortion bows straight lines outward and comes with wide-angle lenses. Pincushion distortion pinches them inward and comes with long lenses. ON, the default, corrects both, and some lenses force it on and grey the item out (pp. 447, 479). In-camera RAW processing cannot change it (p. 265). I leave it ON.

09.Skin Softening and Portrait Impression Balance

Skin Softening

When the camera detects a human face it can smooth the complexion at High, Normal or Low, or leave it alone with Off, the photo default (p. 447). It handles up to three people. With several in frame each gets a grey focus point, and in Auto-area AF left and right choose the one to soften (p. 480). It does not work with some features, among them HDR overlay, multiple exposures and high-speed frame capture +. The video item adds Same as photo settings, its default (p. 579), and is skipped with raw video and with N-Log in ProRes 422 HQ or H.265 10-bit (p. 598). I keep it Off in both menus. For photos the reason is that in-camera RAW processing cannot revisit it (p. 265), and for video it is that nothing can undo it once the clip is recorded.

Portrait Impression Balance

This tunes the colour and brightness of skin rather than its texture. In Mode 1, Mode 2 or Mode 3, left and right shift hue between magenta and amber, which Nikon labels yellow, and up and down change brightness. O resets, J saves, an asterisk marks a changed mode, and choosing a mode turns the feature on while Off, the default, turns it off (pp. 447, 481-482). Once the item is added to the i menu with Custom Setting f1, the main command dial picks a mode there and the multi selector adjusts it with a preview (p. 482). It is unavailable with the three monochromes, the Creative looks and HLG Monochrome, may also shift anything skin-coloured (p. 482), and is disabled by N-Log (p. 216). Unlike skin softening it can be changed in RAW processing (pp. 265, 270). I leave it Off and correct skin per session in editing.

10.Video Picture Controls

The video item adds Same as photo settings, its default (pp. 183, 578, 590). Auto builds on Neutral in video rather than Standard (p. 183), and with Same as photo settings a look chosen for portraits follows you into the next clip. N-Log removes the item (p. 216) and HLG video uses HLG quality instead (p. 215), both covered in the video part. For gimbal dance I set it directly: Standard for clips posted as shot, Flat for SDR clips I will grade.

11.Recommended Settings

Wildlife and birds. Standard, untouched, so a burst matches. At f/6.3, the long end of the Nikkor Z 180-600mm, the diffraction disc is about $2.44 \times 0.55 \times 6.3 \approx 8.5$ micrometres, under one and a half pixels.

Stage dance. Neutral with the Tamron 70-180mm, since stage light is already strongly coloured and added saturation pushes it towards the edge of sRGB. Active D-Lighting stays Off: a dark stage should look dark, and the feature can add noise.

Portraits. Rich Tone Portrait with the Nikkor Z 85mm f/1.8 S, because it keeps skin and highlight detail and is meant for editing (p. 184), with both skin tools Off.

Street and landscape. Monochrome with raw plus JPEG for street, which keeps a colour NEF. Flat for raw landscapes, Landscape for finished JPEGs, and R for the darkest monochrome sky.

12.Beginner Mistakes

Leaving Auto on for a series. Auto, a Custom Picture Control based on Auto, and any A value can render two frames of one scene differently (p. 916).

Judging NEF colour in another converter. Picture Control, Active D-Lighting and Vignette control show only in Nikon software (p. 919).

Posting Adobe RGB to the web. Software without colour management reads it as sRGB and shows it dull.

Forgetting Same as photo settings. A change made for stills quietly changes the footage too.

Loading from the wrong card. Load/save reads only the primary slot (p. 194).

13.Related Chapters

• White Balance: the other half of colour.
• RAW, JPEG, HEIF and Tone Mode: JPEG, HEIF and NEF, and the SDR and HLG tone modes.
• Metering: matrix metering, which suits Active D-Lighting.
• ISO and Auto ISO: High ISO NR for photos and the Hi range.
• Exposure Modes: mode M and Auto Active D-Lighting.
• Card Slots and File Handling: which slot is primary.