Trying to understand colour grading and exposure: Workflow & edits

published Dec 01, 2019 03:10   by admin ( last modified Dec 01, 2019 07:44 )

In this video, beginning at 9:28, Color Grading Central goes through how to make video color grading and light editing in  Davinci Resolve 16: https://www.youtube.com/watch?v=NoyDMKqo80U

Now colour grading video is not something I've ever done, but it so happened I watched this video on the topic and I realised that the info contained might be especially helpful for those of us who just post images and videos occasionally, to a at least get the bascis right.

So here's how I interpret the info in the video: Correcting the color and exposure in a video or image is a lot about using the available dynamic range on screen and in the human eye. In that way the material that you are presenting is using as much as possible of the viewer's perceptual space, so to speak.

1. Start with adjusting the exposure. This means adjusting the darkest shadows to be near black (since then we are then using as much as possible of the perceptual space available).

2. After that, adjust the highlights to near white.

3. After that, the midrange probably sits a bit too high in the image. Adjust the curves so that the midrange spreads out across the perceptual space to give the most detail.

4. Adjust the white balance. Find an area in the image that is supposed to be white, and use that as a reference point to white (in the 1980s I did some video, and back then you would white balance the video camera by pointing it at a white paper and press the "white balance" button)

5. Adjust the saturation of the image, by analysing how much there is and then e.g. increase it, again to fill up the perceptual space.

 

Bonus point, there is an aestethic called "orange/teal" which gives faces a special colour that pops against the background.

 

In professonal video, it seems you often record images with an exposure curve that is unnatural, but preserves the most dynamic. That is, you always need to colour grade in post to get back to natural. This unnatural curve is called "log profile" or "flat profile". The logic seems similar to audio technologies such RIAA correction in record players, and Dbx or Dolby noise reduction: You record in a compressed or expanded way, and then in these audio cases recompensate at playback to improve the signal to noise ratio..