0This article was originally published on PremiumBeat’s blog.
Not long ago, reading scopes was a basic part of a post-production job. The entry-level employee would typically begin learning how to calibrate monitors against test patterns and to evaluate inconsistencies and illegalities in tape workflows in the machine room.
Due to the gradual shift away from tape-based mediums and toward digital mastering, hardware scopes are used less, but still persist inside software. To those video industry creatives who were not trained in the machine room, scopes can be intimidating. Nevertheless, understanding scopes should be part of every video professional’s core knowledge base, and is especially crucial to the colorist. Here are three practical ways to use scopes in Resolve.
Ascertain Color Bias
Scopes can immediately tell you how an image is tinted. I like to grade in a subtractive manner by evaluating what’s wrong with the image and performing the opposite action to correct for the bias. Scopes communicate information in a more efficient way than our eyes, since our vision acclimates to an image within seconds. Our environment also affects how we perceive images, and sometimes grading is performed in suboptimal conditions, like on-set grading environments where a dark environment with neutral grey walls is unattainable. Scopes, on the other hand, present a readout of the visual image that is mathematically absolute as opposed to aesthetically subjective.
Scopes can also be used to balance the whites and blacks. Using the waveform view and the color wheels, the three color channels will combine to create white when there is no color contamination in the highlights or shadows. In the image below, the back wall has a reddish hue, and the scopes confirm this. In the correction, I nudge the highlights to compensate for the color shift to create a true white, which creates a more natural look.
In this image, the wall behind the subject looks strange, and sure enough the scopes read a red-magenta bias in the highlights (blue oval). A vectorscope blob representing the subject’s skin rests below the skin tone guideline (red circle). While the skin indicator is only a rough indicator of where skin tones are likely to land, these two clues will aid in creating an initial correction.
While the image is far from complete, already the image is looking better. The blacks and whites haven’t been too pushed and the highlights are now white, as indicated by the white in the waveform’s upper register. The smudge on the vectorscope representing the subject’s skin is closer aligned to the skin tone indicator, and sure enough the subject looks healthier than before.