White balance and LUT3D

[ejmillan]

Hello again.
I’m still testing to adjust color and improve noise and sharpness in a home recording.
I started in another thread asking about the meaning of oscilloscopes here:

About colour correction and oscilloscopes

I have low-quality home video footage in incandescent lighting. I wanted to correct as much as possible the yellow cast of this video. [PSOk6u0NMS] I started reading about colour correction and colour grading, I watched some tutorials but they were not helpful because they talked about specific tools from commercial video editors, using adjustment layers or even moving masks for local adjustments quasi-automatically, but with the use of these tools there is little talk about manual adjustmen…

Now I did new tests with LUT(3D).
I thought it was easier to load LUT(3D) and observe the result.
With a LUT3D called Kodak_Kodachrome 200, I got more natural-looking colors, however, what left me a bit thoughtful was that the best result was obtained by applying the white balance after the LUT(3D) filter.
does this make sense? I mean am I doing something stupid?

In the footage I find tonal shifts for the same framing, most likely because of the analog camcorder’s automatic white balance. I could fix this if the WB filter had keyframes.
As I guess this is not the usual way to correct this, maybe the color correction filter would be more suitable, but it was so easy to select the white area and get the right look that I am lazy to manually adjust every parameter of the color correction filter.
I tried adding a white balance filter underneath the above by enabling it only on the bits of scene where it doesn’t look natural, but it seems that’s not a very normal workflow.

I mistakenly thought that LUT(3D) would help me balance the color throughout the video, but that was just in my head. Some sort of magic wand that doesn’t exist.

So for these white balance changes that my camcorder made in the recording, what can I do, do I have to make clips and separate scenes and apply a separate white balance filter to each scene?

As always I appreciate the advice.

[Austin]

Here’s the template for an idea:

LUTs Specific

The creator of the LUT or a LUT editor can adjust the intensity, but a LUT captures the state of all color and level changes. They are not inherently adjustable. If other tools do allow you to adjust the intensity, they are modifying the LUT in a simplistic manner. You can reduce the intensity of a LUT or any other filter using filters in this order Mask: Simple Shape with Width and Height = 100% Opacity (here is where you adjust intensity including keframes) LUT (or other filters) Mask: Apply …

…except instead of having LUT as the third filter, put in White Balance. Force the white balance to be an extreme value. If your video generally needs to shift towards yellow, then go extreme yellow. Same if in the blue direction. Then, keyframe the Opacity filter to dial in the amount of white balance that’s needed. The extreme white balance setting gives you some buffer to work in.

I haven’t tested this to work. I’m mobile and making a guess.

[ejmillan]

Thank you very much @Austin.
I read that thread about adjusting the intensity of a LUT, but I didn’t imagine it could be a way to simulate keyframes for white balance (or something like that).
I’ll follow this workflow you’ve proposed and share the results.

I also noticed that the “old film: Technocolor” filter produced some thin red line in the middle of the video in some scenes (maybe a reflection or a thread of light) and increased the noise quite a lot. By using LUT I managed to reduce this yellowish tone present in the whole video, I recovered the natural color and I had no red lines or noise increase.

Today I spent a long time collecting LUTs and trying different combinations. Tomorrow I will try again.
Thanks for your guidance.

[Namna]

@Austin

I haven’t tested this to work.

Et en plus, cela fonctionne!
Superbe astuce pour avoir des images clés sur la balance des blancs.

And it works!
Great trick to get key images on white balance.