Chapter 07
Exposure tools.
Five tools read the exposure of the picture: SCOPE, FALSE, ZEBRA, EXPO and, in photo mode, EXP. They share one idea: they measure the signal the camera records, before the LUT, and they know which log curve the camera is using. This chapter explains each tool, every option, and which one to reach for.
How the tools are calibrated
The thresholds for "clipped", "highlight warning", "middle grey" and "crushed shadow" are not fixed numbers. They depend on the recording profile:
- R3D / Log3G10 on the Nikon ZR and RED bodies. The highlight thresholds follow the ISO and the active base ISO.
- N-Log on Nikon bodies, using Nikon's published curve: black near 12%, middle grey near 35 IRE, clip at the top of the range. N-Log is assumed whenever the codec reports it or the selected LUT's name contains "N-Log".
- SDR (Rec.709 and similar) when neither applies.
The calibration is refreshed when you change the codec, the ISO, the base ISO or the LUT, and frozen while recording so a mid-take change cannot move the guides. With Analyze Pre-LUT on (the default, in Advanced › Monitoring › Scopes), every tool reads the log signal under the LUT; turn it off and they read the LUT output instead.
A contrasty LUT makes an overexposed sky look fine. Because the tools read the recorded signal, zebras and false color still show the clip. Trust the tools, not the look.
SCOPE: histogram, waveform, parade, vectorscope
The scope floats over the picture and can be long-pressed and dragged anywhere. The waveform and parade draw dashed guide lines with their 8-bit code values on the right: C (red) is the highlight clip point, H (yellow) the highlight warning, M (green) middle grey, S (red) the shadow clip point, with an orange shadow-warning line. In N-Log pre-LUT mode S is pinned to code 32 and C to 255; in other profiles the lines move with ISO and base ISO.
Histogram
Red, green, blue and luma counts of how many pixels sit at each brightness, with the calibration bands shaded. A pile-up at the right edge is clipping; at the left edge, crushed shadows.
A quick overall check, especially for stills. It does not tell you where in the frame the problem is; use the waveform or false color for that.
Waveform
Brightness plotted against horizontal position, so the scope lines up with the picture left to right. Read the level of a face or a wall by finding its column.
The default for video exposure. Put faces around the M line plus one stop (the gap between M and H is roughly two stops in log), keep the brightest thing you care about below C, and keep important shadows above S.
RGB Parade
Three waveforms side by side for red, green and blue. For a neutral object the three traces should sit at the same height.
White balance and camera matching. If blue sits higher than red on a grey wall, the image is too cool: raise the Kelvin. If green sits apart from the other two, adjust tint. In Multicam, put a grey card in front of each camera and match the parades.
Vectorscope
Hue and saturation only, on a BT.709 graticule with 75% targets for red, yellow, green, cyan, blue and magenta, a skin-tone line, and a gain note (the display is amplified so small saturations are visible).
Skin tones and colour balance. A face should fall on the skin line whatever the ethnicity; if it sits to one side, white balance or tint is off. A grey card should sit dead centre. Log footage is low in saturation, so the trace looks small; that is normal.
FALSE: false color
False color replaces the picture with a colour per exposure band. Each style has its own set of bands; the legend lists them top to bottom from brightest to darkest.
| Style | Bands (top to bottom) | Best for |
|---|---|---|
| X-Zone | Thirteen one-stop bands from +6 through 0 (middle grey) to −6, scaled to the active log curve | Lighting and ratio work: you can read how many stops a face is above a wall at a glance. The default. |
| ZR Calibrated | Clip, Warn Hi, Near Hi, Upper Mid, Mid Gray, Low Mid, Shadow, Deep Shadow | Everyday exposure on the ZR with the thresholds tuned to its log. |
| IRE Spectrum | Clip, Warn Hi, Near Hi, Upper Hi, Skin Hi, Mid Gray, Low Mid, Shadow, Deep Shadow | The familiar rainbow palette with a dedicated skin band, if you come from other monitors. |
| Cine Classic | Clip, Near Hi, Skin +1, Mid Gray, Shadow, Deep Shadow | A six-band palette that stays calm: most of the frame keeps its colour and only the landmarks are painted. |
| Clip Guard | Over, Mid Gray, Under | The simplest check: three colours for clipped, correct and crushed. Good for fast run-and-gun. |
Setting up a shot or lighting a scene, when you want to see the exposure of everything at once. It is less useful while rolling because the picture itself disappears; switch to zebras or X-Lights once exposure is set. The style can also be changed in Advanced › Monitoring › Scopes.
ZEBRA: zebras
Stripes are painted where the picture reaches a calibrated level. The colours are fixed: red for clipped highlights, yellow for the highlight warning, magenta for crushed shadows, blue for the shadow warning, green for the middle-grey band. There are no threshold sliders; the levels come from the profile, ISO and LUT calibration, which is the same calibration the scope guides use.
While rolling. Zebras leave the picture intact and only paint the problem areas. Use Highlights to protect skies and windows, Mid Gray to put a grey card or a face at the reference level, Shadows to catch important darks falling into noise, and All for everything at once.
EXPO: X-Lights and X-Posts
X-Lights are three columns, one each for red, green and blue. Each column has an upper lamp for highlight pressure, a segmented bar, and a lower lamp for shadow pressure. A lamp lights as that channel approaches its limit in the pre-LUT signal. Because they are per channel, a saturated red light that clips only the red channel is caught before the luma waveform would show it.
X-Posts are two sixteen-segment meters: CLIP (red) for how much of the frame is at or near the clip point and NOISE (orange) for how much is down in the noise floor.
The panel floats over the picture and can be dragged.
The "traffic lights" for shooting: glance at the lamps while watching the picture. Keep all lamps off or amber; a red upper lamp means close the aperture or add ND; a red lower lamp means open up or add light. Pair it with zebras to find where the problem is.
EXP: the camera's exposure meter Photo
A draggable METER panel showing the camera's own light meter: a green marker when balanced within half a stop, orange when over, blue when under, with the value in EV. In manual mode it shows the meter reading; in P, S and A it shows the exposure compensation.
Stills in manual mode, when you want the camera's opinion of the scene without looking at the camera. For video, use the scopes instead; the meter does not know about log.
Which tool when
| Situation | Tool |
|---|---|
| Lighting a scene, setting ratios | False color (X-Zone) to read stops across the frame. |
| Setting exposure for a take | Waveform with the C/H/M/S guides; place faces one stop above M. |
| Protecting a bright sky or window | Zebras on Highlights, or Clip Guard false color. |
| Rolling | Zebras plus X-Lights, so the picture stays visible. |
| White balance and matching cameras | RGB parade on a grey card; vectorscope for skin. |
| Checking a LUT is not hiding anything | Any tool with Analyze Pre-LUT on (the default), or WIPE to see the raw log beside the look. |
| Stills, manual mode | Histogram plus the EXP meter. |
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