The letter

One letter a week, starting soon.

The week's signal, what the makers shipped and what the reviewers found, and the editor's note. No tracking, no ads, nothing else.

We keep your address, your language and the date you joined, nothing else. Every letter has a one-click unsubscribe link that deletes the record.
Video basics3 min read

LESSON 88

Zebras, false colour and waveform

Reading exposure without trusting the screen.

IN THIS LESSON

  1. Why the monitor lies
  2. Zebras
  3. The waveform
  4. False colour
  5. Practice: a simple routine

Why the monitor lies

A small camera screen is set to its own brightness and is often seen in sunlight or a dark room, so it is a poor judge of exposure. Video cameras therefore offer measuring tools that read the signal itself. They tell you where the brightness of each part of the picture sits on a scale from black to the clipping point, regardless of how bright the screen is. Learning one of them well is worth more than any number of test shots.

Zebras

Zebra patterning fills every part of the image above a chosen brightness with moving stripes. Many cameras let you set the threshold, for example 70, 80, 90 or 100 percent, where 100 means pure white with no detail. A lower setting of around 70 to 80 percent helps place skin tones, while a high setting near 100 warns that highlights are about to clip. Zebras are quick and leave most of the picture clear, which is why camera operators often keep them on all day.

The waveform

A waveform monitor began as a special oscilloscope for television. It plots the brightness of the picture from left to right across the frame, with black at the bottom and full white at the top, so you see at once if a sky is clipping or a face sits too low. Broadcasters used it to line up several cameras so they match, to check signals stay within legal limits, and to set exposure on video and digital cinema cameras. Most modern units combine it with a vectorscope, which shows colour.

False colour

False colour is a monitor mode, offered on many cameras and field monitors, that paints brightness levels in set colours: often purple or blue for crushed blacks, green or grey for middle grey, pink for skin and red or yellow for clipping. The exact colour scheme varies by maker, so check your own camera's chart. This section is a description of common practice; the colours are not a universal standard. The strength of false colour is that it shows the whole frame at once and needs no reading of a graph, which makes it handy for checking faces quickly between takes. Its weakness is that it hides the picture while it is on, so most operators switch it on, check, and switch it off.

Practice: a simple routine

This is working practice. Set zebras to just below clipping, so stripes warn you of lost highlights. Check the face with false colour or a second zebra level for skin. Glance at the waveform before each new set-up to see the overall spread. Then trust the tools over the screen. When you move to a new location, repeat the routine rather than assuming the last settings still hold, because a cloud, a window or a practical lamp can shift the whole picture by a stop. Keep the same zebra levels on every camera of the shoot, so that two operators read the same warning for the same brightness.

Try it today

  1. 01Turn on zebras and set them to 95 or 100 percent.
  2. 02Point the camera at a window and open the iris until stripes appear.
  3. 03Switch on the waveform and find the window at the top of the trace.
  4. 04Frame a face and note where skin sits on the waveform.
  5. 05Write those two numbers on a card for your camera bag.