LUT and nodes

[Eric Johnson]

Why can’t you put the LUT on Node 1, then do your primary on that node? There is nothing stopping that from happening as far as I can tell.

[Margus Voll]

i always use lut on first node and do balance there if i like.

Some people leave first node as is and use second node. it is just the workflow thing i think.

—

Margus

https://iconstudios.eu

[Stig Olsen]

Ok, I did read some place I cant remember that is was important not to add the lut to the first node. Anyone?
What exactly does the alexa-LUT do? Do you always use this when grading RED footage? Something get easier using the LUT?

[Mike Most]

Not blowing my own horn, but I did write a pretty detailed explanation of all this on my blog, mikemost.com.

As for the specifics of where to put a LUT in the processing path on a Resolve, what’s important is to have the ability to grade before and hopefully after the LUT as necessary. In the case of Resolve, if you enable a LUT on a node, it is the last transform in the processing path for the node. Anything you do on that node is, be definition, being done before the LUT. So the end result is basically the same as using a separate node fot the LUT itself, The reason some do the latter is because it’s easier organizationally to know where the LUT is so that you can control what you’re doing before it and what you’re doing after it. It also allows you to have multiple nodes prior to the LUT rather than just one.

Read the blog posts and if you still have questions feel free to ask them.

[Stig Olsen]

Ok, thank you Mike.

But that should basically mean that it doesnt matter if its on the first node or not? Since the corrections on that node mathematically is done before the LUT?

Therefore it seems pretty useless to apply a node one the second node if you did some expose controls on node 2. The LUT will mess up your exposure controls anyway – isnt that right?

[Mike Most]

I really don’t understand your question. There are things you want to do before the LUT, and things you might want to do after, such as keys (they work better if you have proper contrast and saturation, which you do after the LUT application) and “final tweaks.” The nice thing about a processing pipeline is that you can have both.

[Margus Voll]

i wonder why do you want to use alexa lut on red ?

—

Margus

https://iconstudios.eu

[Mike Most]

You wouldn’t, at least not one with the Arri color matrix included. However, if you use the Arri LUT builder and create a LUT that goes from LogC to Video, with no matrix and extended range, you’ll have a LUT that works very, very well with Red material that’s processed through the RedlogFilm gamma curve.

[Mike Lary]

Hi Mike,

I built an LUT via Arri’s LUT Builder with the specs you listed, and when I add it to a node for RED source footage (RC2/RedLogFilm), the highlights are clipped at 95%. If I apply a grade to nodes further down the chain, I can bring the levels up, but I can’t grade or make adjustments before the LUT because of the clipping. Do you know what might be wrong?

Here are the settings I chose in the LUT builder:
LogC
Extended
Colorspace: None(1D)
Scaling (tried both options)
to
Gamma: Video
Range: Extended
LUT Parameters (tried 1D and 2D)

Mike Lary
Digital Factory
Seoul, South Korea

[Mike Most]

Please re-read the previous posts in this thread. If the original material has been clipped in the camera there’s nothing you can do about it. But if it isn’t, doing a correction prior to the LUT will put it in proper range. If the LUT is applied on a node, it is the last thing evaluated in the node, so anything else you do on that node (or any node prior to it in the chain) is, by definition, before the LUT.