Classroom in a book

Working with the Waveform Monitor
The Waveform Monitor represents luminance (or brightness) in a graphical form in 
real time as the video plays, using the IRE scale with brightness values from below 
0 to over 100. The brightness value of each pixel in the video frame is represented 
by the waveform graph. The higher the graph, the brighter the pixel.
A well-exposed scene has brightness values across the entire scale. It is easy to 
see that pixels that are all dark would make a dark video or that pixels that are all 
bright would make a bright video. But it is also important to understand that hav-
ing brightness values across the entire scale gives a feeling of depth to the image. 
Having brightness values across the entire scale is called 
range
. Let’s take a look at 
some examples of good range and bad range using the Waveform Monitor as a tool.
#
 Note:
The IRE scale 
stands for Institute of 
Radio Engineers.

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ADOBE PREMIERE PRO CS5 CLASSROOM IN A BOOK
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1
Select the clip named normal.mov. Play it by clicking the Play icon near the 
bottom of the monitor.
2
Observe the Waveform Monitor.
The luminance or brightness values have a nice range, from just below 7.5 (the 
normal low range for black) to about 100 (the normal high range for white), with 
the brightest pixels in the face around 70–75, which is good exposure for a moody 
shot like this one. This clip is an example of a scene that is properly exposed.
3
Select the clip named dark_loud.mov. When you play this clip, notice that 
the pixels that correspond to the face are all below 60 and that most of the 
brightness values are clumped at the bottom, including lots of pixels below 7.5. 
This means that detail in the darker pixels is likely lost for good and that the 
video will look “dark” when played. When you see a waveform like this, you 
should consider adjusting the exposure on the camera or changing the lighting 
to provide a greater range of luminance. Observing the Waveform Monitor 
while you make lighting changes is a good way to know when you have it right.

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