Lumetri Scopes display color information about image. It is used for color correcting footage. Computer monitor, ambient lighting in room can affect how you see color in image, so scopes are used to get the best color results possible.
It shows the intensity of both the luminance (brightness) and chrominance (color) levels of an image, depending on the waveform you choose. Waveform displays the gray-scale values in the image under the playhead, where left to right matches the image left to right, but up and down indicate the gray-scale value of the pixels in the image. It shows intensity in IRE units (scale to the left), ranging from 0 – 100, with 0 being black and 100 white.
RGB waveform shows the RGB signals overlaid for their respective signal levels. Luma waveform displays the brightness of shots and the contrast ratio. YC Waveform display luminance and chrominance. It displays luminance information as a green waveform and chrominance information as a blue waveform. Chrominance information is overlaid upon the luminance waveform. Bright objects produce a waveform pattern (bright green areas) near the top of the graph; darker objects produce a waveform toward the bottom. YC with no chroma display just the luminance.
Premiere offers two different flavors of the vectorscope: YUV and HLS (Hue, Lightness, and Saturation). Vectorscope YUV displays the color values in the image under the playhead, where the angle of the pixel represents the hue and the distance out from the center represents the amount of saturation. Pixels at the center of the vectorscope are gray. Color hues start with Red in the top left and, rotating clockwise. Red transition to Magenta to Blue to Cyan to Green to Yellow and back to Red. A black-and-white image produces only a dot at the center of the chart.
When you adjust the color hue and intensity, the pixels will expand outward as the image becomes more saturated. It contract inward toward the center if the image is closer to black and white. Color indicator boxes are there to tell you if your colors are within the legal broadcast limits.
RGB parade scope is much like the waveform monitor. It shows the color’s intensity levels of a video signal from bottom to top. However, RGB parade scope shows an isolated view of each color channel — red, green, and blue. This differs from the RGB waveform scope, which displays the three color channels as a composite. The RGB parade scope is useful for basic color correction. For example to change white balance / color temperature, and/or matching colors between several shots.
Histogram shows the distribution of pixels in an image from pure black at the bottom to pure white at the top. It gives the global or overall tone levels, as well as the individual red, green, and blue channels. The histogram allows you to view tonal values, including the highlights, midtones of image. It is useful in basic color correction tool to adjust levels (highlights, midtones, and shadows).