Some problems with LUT

Is something not working like it should? Let us know.
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2021-10-31 09:32:58

Hi,

I have converted a lot of preset in LUT for Pixelmator Pro, I know that cannot be equal at 100%, but the results it really cool like the program that start with Light...

Now, when I choose LUT the colors is correct, but when I convert the LUT into regulation, something goes wrong.

Here it is some photo:

Image

Image

LUT selection, color is perfect, except for the quality, as you can see there are many artifact, this happens with all LUT and all images, this the reason that I cannot save directly without convert into regulation

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Image

After doing that...

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Image

Colors is wrong now, like the bike logo, from red became violet.


Any ideas about this problem?
User avatar

2021-10-31 10:36:39

Hi, Husci

This one looks really important. Can you please provide the following information:
1) Sample image file;
2) Sample LUT;
3) OS version and information about the hardware you use (GPU, CPU).
User avatar

2021-10-31 10:48:50

Hi, Anton,

I have MacBook Pro M1 - 16gb ram version with OSx Monterey

Original photo and LUT here: https://we.tl/t-SZS0Pq8zvF

Thanks
User avatar

2021-10-31 20:38:59

Husci, what is the source of LUT you use? How did you get it?
User avatar

2021-11-01 07:36:26

Hi Anton, i converted some preset bought for LR, i use an online tool.

In LR apply the preset on this image:

Image

Exported in .tif and converted into .cube on the website whit the tool
User avatar

2021-11-01 09:49:38

I have reproduced the issue and came to a conclusion that LUT file is a cause here. In simple words, LUT file is “noisy”. I think this is related to the way it was obtained. The results of this LUT application are the same in other LUT-capable software.

I have a suggestion that may help you to get better quality: apply Lightroom preset on higher resolution image and then reduce the resolution back before passing to online conversion tool. For this to work, Nearest Neighbor resampling algorithm should be used.

Step 1. Open this 512×512 image in Pixelmator Pro, and increase it size by 300% (or, better, 500%) by Nearest Neighbor algorithm:
Image

Step 2. Export larger image as .png or .tif file and open it in Lightroom.

Step 3. Apply preset in Lightroom and export it as .png or .tiff

Step 3. Open result in Pixelmator Pro and decrease resolution back to 512×512:
Image

Step 4. Export the image as .png or .tiff file and use online conversion tool on it.

Hope this helps.
User avatar

2021-11-01 10:27:14

Anton,

Its work, no artifact in the sky

When i convert into regulation become violet again, but no problem, now I can export directly without this step

Thanks a lot!