What's the difference betweenViewing, Input and Output LUTs?

[Justin Quinn]

What's the difference between Viewing, Input and Output LUTs?

Would you ever any of them simultaneously?

 

[Luis Otero]

Viewing and Output do the same thing to the image you are viewing via monitor/projector. However, at the time of exporting, Output gets backed-in into your images, as opposed to the Viewing one, which is not backed-in. Viewing is usually used for film-out, which you need to view how the print emulsion will react to the Log image being beamed out into it at the printer. The Output is used for Broadcast/DVD, BD, which you need the image to have the full colors already as part of the footage.

As to the Input, I am not that familiar. I only use it when I receive linearized footage, and I use a LUT to convert it into LOG images to start the color grading.

My 2 cents...

 

[Justin Quinn]

Viewing and Output do the same thing to the image you are viewing via monitor/projector. However, at the time of exporting, Output gets backed-in into your images, as opposed to the Viewing one, which is not backed-in. Viewing is usually used for film-out, which you need to view how the print emulsion will react to the Log image being beamed out into it at the printer. The Output is used for Broadcast/DVD, BD, which you need the image to have the full colors already as part of the footage.

As to the Input, I am not that familiar. I only use it when I receive linearized footage, and I use a LUT to convert it into LOG images to start the color grading.

My 2 cents...

Thanks, Luis.

I'm still confused on the Input LUT issue because when I called BMD tech support, they told me to start with an Input LUT and place it at the beginning of a node tree.

I also find the explanation in the user manual confusing:

"1D and 3D LUTs process the current timeline before every other image processing operation in Resolve. 1D/3D Output LUT let you add 1D or 3D LUTs that process the current timeline after the operations applied in the Color page, but before the temporarily applied Display LUT"

Is that the same thing as saying Input LUTs are like placing the LUT as the first node in the node tree and grading from there... while an Output LUT is like placing the LUT as the last node and grading within the preceding nodes?

 

[Peter Proniewicz-Brooks]

Thanks, Luis.

I'm still confused on the Input LUT issue because when I called BMD tech support, they told me to start with an Input LUT and place it at the beginning of a node tree.

I also find the explanation in the user manual confusing:

"1D and 3D LUTs process the current timeline before every other image processing operation in Resolve. 1D/3D Output LUT let you add 1D or 3D LUTs that process the current timeline after the operations applied in the Color page, but before the temporarily applied Display LUT"

Is that the same thing as saying Input LUTs are like placing the LUT as the first node in the node tree and grading from there... while an Output LUT is like placing the LUT as the last node and grading within the preceding nodes?

Pretty much.

Basically:

1.Input LUT: Applied before everything (apart from RAW/DeBayer settings) including any nodes. This can limit how much more you can do to a particular clip, but unless its drastic you should be fine. Often used to ceate a starting point for a quick grade. Affects exported clips, displays, everything basically.

2. Output LUT: Applied after all nodes etc, can be used to add a look to footage after it's all been matched. Allows more grading leeway than the Input LUT.

3. Display LUT: Applied last, but critically does not affect exported clips. For monitoring purposes, can be used as part of regulating a colour critical display, or be used to show you what output on certain mediums would look like, different Film stocks is fairly common, but I have heard of it used to allow the colourist to see what it will look like on a known display.

In most cases you can use a LUT based around one purpose, for another, so a display LUT (say a film stock LUT) can be added as an Input or Output LUT so exported clips have more of the characteristics of that film stock. Input LUTs designed to flatten an image to give a LOG like starting point would be a bit odd to use as either a display or Output LUT though.....

 

[Luis Otero]

If you use it within a node, it only affects that clip. If you add it at the preference level, it applies universally all clips within the timeline.