LUTS - Can the look be replicated in LR?

Forum|Forum|3 years ago
October 12, 2022
4 replies
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I hope that this is the correct forum and not the Color Theory forum.

From what I have been able to understand from online videos, the major use of profiles in LR is to get a starting "look" to the photo, which can then be further processed with Develop module controls. In the several videos that I have watched it is implied but not actually stated that the "look" of the profile cannot be achieved by just using the Develop module controls. If I understand it properly, this is because profiles have an embedded LUT.

Is my understaning corect? Is it not possible to duplicate the look of a LUT with the Develop module controls, specifically the Color Temperature and Tint controls?

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M

MarkNFAuthor

Inspiring

Thanks to all for your answers. Actually the reason for my question is really not complicated. Profiles and their incorporated LUTS add yet another variable into my post processing if I am unable to come to the same look by using a "standard" profile. I was hoping that by using the various LR tools I would be able to replicate any color scheme that a LUT created. I will follow the links that Rob Cullen has provided.

I've been a LR user since v2.1 and frankly never paid any attention at all to the profiles. Apparently I should have. In looking at my older photos that were made with Canon cameras I see that most have the ACR 4.4 profile but some use Adobe Standard. All the CR2 files were converted to DNG's. My more recent photos have been made with Olympus cameras and the profile used is Adobe Standard.

But in all instances I processed the photo until I got the result I was happy with. Now it seems that there is another variable I need to deal with and the end result will depend on the profile chosen. The obvious thing to do is to just start experimenting to see for myself.

Thanks again.

johnrellis

Legend

Your end goal isn't clear from your post. But if it's to get the same look in LR as in existing LUTs you have or may be acquiring, there's a little-discussed issue with making creative profiles from LUTs:

Most LUTs you find online in "LUT packs" are designed for use with video, and they are in the Rec 709 color space (the most commonly used color space for video). But Camera Raw doesn't provide Rec 709 as an option when making creative profiles -- the closest you can do is sRGB. The two color spaces are similar, using the same RGB primaries, but their tone curves differ in the shadows.

If you import a Rec 709 LUT into a creative profile, specifying the sRGB color space, you won't get the exact same look. The differences can sometimes be quite noticeable in the shadows.

I don't think the Camera Raw developers were aware of this issue when they implemented creative profiles, and they've ignored feature requests to provide Rec 709 as well as sRGB. I think they were thinking that the LUTs in creative profiles would be created from scratch (e.g. in Photoshop) specifically for use with Camera Raw/LR, and they didn't anticipate that people would want to duplicate in Camera Raw/LR the looks they were getting with existing video LUTs.

Conrad_C

Community Expert

Is my understaning corect? Is it not possible to duplicate the look of a LUT with the Develop module controls, specifically the Color Temperature and Tint controls?
By @MarkNF

Not specifically with those two controls you mentioned, because they can’t do the color replacement that an actual color look-up table (LUT) does. Temperature only shifts color along the blue-yellow axis, and Tint only shifts color along the green-magenta axis. That’s all, and that specialized scope is why there are additional panels and features for other kinds of color adjustments.

As in the links Rob posted, the way a LUT gets applied in Lightroom Classic and Camera Raw is to build a camera profile that incorporates a LUT (which could be created in Photoshop), save it in the right location where Lightroom Classic will load it, then apply the profile in the Profile Browser in the Basic panel.

The panels in Develop that act the most like a LUT would be Color Grading and Calibration, but even those cannot exactly do what a LUT does. So you can use some panels to create LUT-like effects, but if you need a correction that relies on true replacement of a color lookup table, then you have to use a LUT.

(And it’s important to note that these camera/creative profiles are not the same as the ICC color profiles used by the OS for display or printing. A profile is also functionally different than a preset.)

This is another good article on using LUTs, with a video, by Blake Rudis. He uses Camera Raw, but Lightroom Classic works the same way.

https://f64academy.com/lut-profile-best-practices-video/