When I started editing videos, I knew nothing. I didn’t know how to use the editing software and I certainly didn’t know anything about color correction or color grading. For the first several months, I just tried to soak up all the information available on the community forum and learn stuff through video tutorials browsing internet.
As a photographer, I always adhere to some rules and refer to histograms, would it be in Lightroom or Photoshop, and I adjust skin tones by numbers. This is how I learned to do it and I find it very helpful for me. I have to admit my intuition is not good and I can’t trust my eyes, simply because my vision is not good, this is why referring to the graphs and diagrams is something that ensures me that my edits are clean.
Today, I’d like to go through the waveform scope and show to you why I use it and how I read it. Just in case you missed the first tutorial “Introduction to Video Scopes” you can read it HERE.
What is a waveform scope and where did it come from? So, when television began it was only in black and white and it was analog video ruled by engineers at every step of production process. They were making sure that video displayed properly on every television adhering to some rules and ensuring that rules met technical requirements. And a testing instrument that was used to perform the measurement of video signal was called a waveform monitor. Later on, when color came along a vectorscope has being developed to verify the color portion of the video signal (we will talk about it later in another article).
You might have a question why we need to verify those things? Simply because the complete range of colors that can be captured on camera and displayed by our computers has a much wider gamut (range of colors) than those that encoded for web or used on a TV set. In other words, what we capture on our camera has to be translated electronically to a monitor and then the monitor has to translate that video information again when encoding for video output. Videoscopes help us to verify the video output is correct.
The image above is of a YC no Chroma Waveform scope, which displays only the luminance values in a clip (Y stands for luminance and C for chroma). This is the Waveform I prefer to use to adjust my images, but you are more than welcome to play with other waveform types to evaluate an overall exposure. A YC no Chroma Waveform scope helps me in color correction for setting exposure and evaluating the brightness of my images, regardless the color. The scale of the YC no Chroma Waveform displays the IRE values from 0 to 100, allowing you to effectively analyze the brightness of shots and measure the contrast ratio. IRE stands for Institute of Radio Engineers, the organization that introduced this standard. Using the waveform scope, I can evaluate how bright or dark my image is. Anything below 0 (black level) at the bottom of the scope will be clipped, and levels above 100 (white level) near the top of the scope will also be clipped, so preferably you want to keep your levels within the 0-100 range, however it is possible to exceed the 100 IRE threshold and not to clip your highlights. For now, I'd stick to a 0-100 range.
Now let’s jump over to Premiere Pro and use the Waveform scope to technically evaluate a shot. If you are a Final Cut Pro or a DaVinci Resolve user, I ensure you you will be able to follow along.
Thank you! Happy to answer any questions.