LUT problem Affinity Photo

[BernardB]

Hello,

I want to make a conversion table to process some scuba diving videos for a friend.

I got an image and I applied a level adjustment to it to improve the colors.

Then I export the conversion table in 17x17 cube format, 64 x 64 its the same.

If I then apply the conversion table setting with the table I created nothing happens !

I tried with AP V1, V2 and V2 beta, same results everywhere.

If I apply a table retrieved from the internet it works.

Where is the problem ?
Thanks

Translated with www.DeepL.com/Translator (free version).

LUT plongée.cube

[David in Яuislip]

Could it be this, nested adjustment layers are not included when exporting LUT?

[Circulus]

58 minutes ago, David in Яuislip said:

nested adjustment layers are not included when exporting LUT

They at least should be able to be grouped.

[BernardB]

Yes, but as you can see, on the screen copy of layers, i was not working with nested layers.Thanks

[iconoclast]

I already had a similar problem with the Levels Adjustment and LUTs in Affinity Photo 1, a long time ago (LUTs created from adjustment...). As far as I remember, the Master channel adjustment wasn't inherited by the LUT-Export. As an Admin told me, it was a bug. I'm not sure about it, but possibly it isn't fixed yet. I can't remember if it is the only filter that causes this problem. Possibly it will work with the Gradation Curves. But without warranty.

Edit: as an additional hint - I used to create LUTs for a long time using GIMP with the free G'MIC-Plugin, that has some filters concerning LUTs. G'MIC also exists as 8bf-Plugin for Photoshop and Affinity Photo, but it is not fully compatible with AfPhotos layer system, as I experienced. Most filters also work with AfPhoto, but a few don't, like this one. In G'MIC, there is a filter called "CLUTs from after/before Layers" in the "Colors" category, that is very useful to create LUTs from two images, loaded as layers - one in it's initial condition, one in the final condition.

Edit: and another additional hint. There is also a filter called "Color Presets" in the same category, that already contains a huge amount of very good LUTs. This filter should also work with AfPhoto, I think.

[BernardB]

Nice Iconoclast, you are right.

I made same correction with curves and the Lut works as well as curves !!

Bug is'nt fixed yet ! It's in all versions of AF.

[iconoclast]

I was afraid you would say that. What about trying GIMP with G'MIC for this task, as I mentioned above. The LUTs can be used in AfPhoto and other apps too. You can edit target image with AfPhoto, export it, open the source image in GIMP, simply drag the target image on it as a second layer and then apply the filter. For me that worked pretty good.

[BernardB]

Yes Iconoclast, there are solutions by taking other settings or using Gimps, but in my case I'm trying to manage a table for a friend who makes underwater videos and I thought Affinity could do it easily.
It almost does, but there's an old bug hanging around and it's not the only one ! 😖
This is not a criticism of Affinity but a wish to improve it.
I trained the members of my photo club in Affinity, so I am convinced of its efficiency !😉

[iconoclast]

Yes, it is of course annoying that this bug still exists, but that's the current state. I only tried to offer you a workaround. And that worked for me very well - even it is of course a bit more circuitous as if it would work in AfPhoto directly. And if you have created your LUT, you can load and use it in AfPhoto as intended. The bug only concerns the export of the Master Channel to the cube file, it's not a general LUT-problem in AfPhoto.

Probably this function is not on the top list of the developers to fix it, because it is not one of those functions that are important to the majority of users. I'm sure they are busy, but a software like AfPhoto is a very complex thing.

I personally use GIMP anyway for a lot of handicraft. Even it is not really a serious substitute for AfPhoto, it has some functions that AfPhoto and other image editors doesn't offer. So GIMP - especially in combination with G'MIC -  is a very good supplement.