There's a lot of advanced correction that you can do in the log space with video apps' native tools, like masked corrections or graduated filters. And I'm not focused purely on basic adjustments. It needs to be multithreaded or use GPU acceleration. It's not easy to make a plugin that performs well. Vitaliy, I don't want to reinvent the wheel when we already have good-enough plugins for loading LUTs. If you are used to Kelvin sliders, treat the blue channel like Kelvin and the green slider like tint. You only need two of those, but having all three makes it easier. With three sliders you have three axes on which to make the adjustment: the red-cyan axis, the green-magenta axis, and the blue-yellow axis. I wish all the apps would use RGB sliders. Thanks, What camera do you use now? It'd be nice to see some samples posted as people start working with in my experience RGB sliders are the best way to do white balance adjustment - better than color wheels or a Kelvin slider.
What's notably missing is support for Adobe Premiere Pro and After Effects, which I'd imagine is not an oversight, but due to more substantial issues? Balazar's log color space conversion fills in that gap, allowing you to alter exposure, white balance, and contrast within the host application. This partially compensates for the absence of a global white balance adjustment, which cannot properly be performed in Rec 709 color space. With video color grading tools, it's more common to provide separate sets of calibrated adjustment controls for highlight, midrange, and shadow regions, as well as a master set of controls for the entire histogram range. It's a subjective interpretation rather than a calibrated adjustment. For example, the effects of Adobe's "contrast" control vary depending on which process version you select in ACR. As with most photograhic software, Adobe Lightroom treats exposure, white balance, and gamma globally across the histogram range, and provides its own custom controls for separately adjusting highlight, midrange, and shadow properties.
Regardless of the working color space, what's open to personal opinion is how to best manipulate the footage with post-production tools. The color science behind this is well-defined and valid to the level of color fidelity recorded in the original footage. In that situation, you must work with the exposure, white balance, and gamma profile that were selected at the time the footage was shot.Ĭonverting H.264 footage into a standardized log color space (in this case a version of ProPhoto RGB), allows exposure, white balance, and gamma curve to be adjusted in post-production, similar to how Adobe Lightroom uses ACR to manipulate these properties in RAW photographs. Normally when grading H.264 footage, you're working in a Rec 709 color space, either natively or converted from a log profile into Rec 709 by a calibrated 3D LUT. As with JPEG versus RAW still photography, these properties are burned into H.264 video recordings, regardless of whether you shoot in log or Rec 709 profiles. The major bullet points here are exactly what Balazar points out: global adjustment of exposure compensation, white balance, and contrast.