Matt Floryan

setting a proper balance dealing with log type footage

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This seems like a basic question but wanted to get some insight on it. It is all about setting a proper balance dealing with log type footage. When using a film emulation LUT to expand contrast and implement a color "look", the image is going to have some type of color bias built into the math of the LUT. How are you suppose to "balance your shot" when using a LUT like this? I understand that you want to balance your shot to correct for any white balance issues but how are you suppose to achieve this with a film emulation LUT? Do you expand the contrast manually, add another node and apply balance, then reset the contrast node and apply the film emulation LUT?  I hope this makes sense. thanks so much for your help.
 

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A creative look-up-table comes with modified properties like a certain degree of saturation, print tone scale etc, which mean that it will set the balance off from the first time it's applied. You could balance the image, use a inverse LUT to set it back to Log again and then apply your creative LUT at the end of the chain. That said, t's more common workflow to use a normalization LUT and dial in the preferred look manually.

 

 

 

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I agree with the above, unless you use a creative LUT in a linear color space. That will let you balance the image and apply the creative LUT afterwards. 

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You should check out Juan Melara’s tutorial on Resolve using Colorspace transform FX - it shows exactly how to do that.


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Welcome to this forum Matt!

The Print Emulation LUTs were originally applied to the end out the chain to see how the grade would look when printed on a specific film stock. This was necessary because the look of the digital film master was radically changed once printed on a stock. E.g a Kodak 2393 LUT were used to look through if the destination stock was Kodak 2393.

Today, we don't need to use the film LUTs this way, simply because the digital master files are not printed on film.

What  you are describing is a modern approach where the same data is used creatively in the color process. If you want that to work properly, it still means that the LUT should be applied at the end because if you do any corrections after the LUT is applied, the calibration will break or the pre-defined and intended look will be changed. That also means that the LUT will be applied after the initial base correction with a log to linear transform, which means that the image isn't logarithmic anymore. That is a problem because the typical so called 'creative' print emulation LUT's have a built in ormalization curve. 

So, as suggested above, you need to use an invert LUT to transform the image back to log state after your initial correction. Or, you can use a LUT ment for linear input data.

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