I'm very new to Davinci, but I've been checking out a bunch of tutorials.
I found a great LUT I liked a lot. I jumped into the project settings and used the LUT as the 3D input option. I looked fantastic, until I got like half way through my clips. About halfway through, the shots get a bit darker and the LUT just destroys them. (almost unsalvageable) So, I tried using the Output option and also just applying the LUT to each individual clip via nodes. Those options worked with the darker clip but the first half of the clips never look as good with the other two option as when the LUT is applied to the 3D input.
So, in a long winded way my questions would be; If I use the 3D input LUT can I override that on individual clips that the LUT is ruining? Also, why do these options create such drastically different results even though its all the same LUT. ( I get that input bakes the LUT in first and Output allows you to make changes and the LUT is applied at the end)
I feel like I don't have a good grasp on the theory of what is actually happening with a LUT which is making it hard for me to understand how to correct problems that it creates.
As you have discovered, it makes a huge difference if a LUT is on input or output, in other words if you are grading before the LUT of after.
If you want more control, just use the out as a node in your node tree and either place your grades in front or behind it.
That said, I would suggest doing a bit of research on this, and using LUTs as they were designed to be used, either as input or output LUTs.
Typically an input LUT is designed as an input transform to move a specific type of footage into a known working space. For example to take Sony Slog and put it into a film log (cineon) working space, etc. An output LUT is typically designed to take a graded input from a known working space and transform it, targeting a specific display color space. If you disregard these factors and just throw LUTS on randomly irregardless of how they were designed, what color space they were designed to be coming from, going to, input vs output, your results will likely not be great.