Learning how to read and implement the information displayed by your scopes is a crucial ability for any colorist. Much like a good pilot, a good colorist relies on their instruments, not what their eyes tell them. Of course, a good broadcast monitor is useful in getting a sense of your image, but your scopes should be your primary point of reference when making adjustments.
We recommend using DaVinci Resolve for your color correction needs. If you are using another program, you may find that some of the specifics in this overview are different in your program of choice. To read up on DaVinci Resolve, check out our introductory guide to it.
Waveform Monitor
Your waveform monitor displays the luma values of your image. The y-axis travels from absolute black at 0 to absolute white at 1025. The x-axis simply matches the horizontal layout of your image. Conceptualizing how your image is displayed here can be difficult at first, but once you learn to read a waveform, you'll be able to identify specific parts of your image in the waveform.
What does this waveform, for example, tell us?
Well, on the right, we can see that the image is dark based on the way the lines are clustered bellow 512 (the midpoint). We can also see that the rest of the image appears somewhat blown out, as evidenced by the thick white lines at the top of the waveform monitor. What overall color tone would you guess this image has? Notice that the blue lines are consistently higher than the red lines, which are mostly higher than the green lines (white lines indicate overlap between the three). That means that this image will have a magenta tint, with perhaps a leaning towards blue, as red + blue is magenta.
Parade
The parade monitor is very similar to the waveform monitor, but it displays the RGB channels side by side instead of overlapping them. This view can be useful when targeting a specific channel, but generally, you'll want to refer to the waveform monitor over this scope.
Vectorscope
The vectorscope displays the hue and saturation values within an image. Hue is indicated by the direction of the lines within the vectorscope, while the length of the line indicates the saturation of each color value. For example, a line reaching most of the way out to the "R" symbol would indicate an image with lots of very saturated reds.
What does this vectorscope tell us?
It can be hard to see, but there's a concentration of white in the exact middle of the scope. Keep in mind that the vectorscope displays all greyscale elements of the image on the center of its display, so that marking could indicate an image with a spot of white, black, or anything in between. Branching out from the center, We see a line pointing definitively towards C for cyan. This means that the image is mostly cyan in hue. Increasing the saturation of the image would force the line further towards the C marking, while increasing the luma towards absolute white or decreasing it towards absolute black will shrink the line.
Histogram
The histogram can be read like a tipped-over parade monitor. The left side of each histogram (R,G,B) represents absolute black, while the right side represents absolute white on a scale from 0% to 100%. The y-axis plots how many pixels in each color channel hit each percentage point of luminance.
What can we tell from this histogram?
First, it's clear that this image is fairly dar, as all three histograms are weighted towards the left of the spectrum. On the far right, you might notice a spike in the red value and a smaller increase in the green and blue values. I know that this spike represents the streetlight that is in my image, so if I wanted to make that streetlight less red, I would pay attention to my histogram while making adjustments. We can also tell that this image is fairly well-balanced, as the red, green, and blue histograms follow a similar profile. You don't necessarily want a perfectly matched profile, as that would mean your image is greyscale, but for most images, a histogram like the one above indicates a well-balanced color space.