Sigmoid module advice and guidance needed

do you have filmic activated or deactivated when using sigmoid?

For me, filmic deactivated. I saw a post in the main sigmoid thread explaining that using both at once has unintended results. I tried using both - not good! That was only on one or two images but it’s certainly not the intended use, as far as I know.

They are both expecting scene data not display so using both makes little sense…

Yes. Here’s the post I was thinking of: Evaluate the new sigmoid tone mapper just merged into master ... - #85 by jandren
Near the end of the post @jandren says the same thing…

Haven’t tried to use it, but looking at that GitHub explanation, I’ve no idea what it’s trying to do. With filmic, after reading some stuff and watching a video or two, I can understand the concepts behind it and what any changes are used for, even if that’s just a gross simplification of the activity under the hood. That’s what sets DT apart for me, rather than the ‘waggle the sliders randomly until it looks ok’ approach of other soft. Hopefully someone will explain at some point what the aim of this function is (that doesn’t involve wading eyeball-deep in a squillion post thread). Thanks

Basically the same thing as filmic using different math…its a based on a log - logistic curve so not the same space as filmic…

As for use pretty simple contrast slider… pretty self explanatory and skew… slides the point for the peak contrast and then a couple of hue preservation modes… no gamut mapping I don’t believe and of course no filmic highlight recovery tool either…

So the math of the curve is handling the global tone mapping and you can tweak contrast and where that peaks with the skew… and then address color shifts as you like…

Simple thing is to just try it on a few images and if you prefer one over the other just use it…

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Thanks Todd. I will obviously give it a go when I get chance. I guess filmic is more intuitive theoretically because its interface is like a souped up tone curve that most ordinaries understand. That quote you used above kind of makes my point. (I have no clue). It’s a knife edge giving a certain amount of control and comprehension to people so they don’t feel like they’re a dimwit who needs their shoelaces tying on the one hand or in need of a phd on the other

It’s early days, obviously, but it seems this is going into DT at some point, right? I guess there’ll be a need to get across to relatively avg users what they’re waggling with those sliders at some point, in the same way different people managed to do with filmic.

Really Tony its not that hard and there was a massive 700 plus thread documenting the evolution with lots of test images and comparision…even this thread already has many so its not going to be that challenging…use the first two sliders to manage your tone and then slide the chroma preservation to your liking…rgb ratio is more like a filmic method of hue preservation so you will see the salmon colors at times other times it can be nice… Thats really it…set your exposure and then tweak sigmoid module…and really often IMO so far not much waggling needed…

Edit sorry not this thread but the one I started for evaluation of Sigmoid …

I think I already mentioned the 700 post thread as a negative. My point is not that it will be difficult to use, I’m making the case that at some point it would be useful for people not into reading 700 unstructured posts what it’s all about in terms somewhere between teaching your grandma to code and teaching her to suck eggs (excuse the sexist, ageist metaphor). Trying to be helpful. Thanks

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I often use the dehaze preset of D&S…this is plenty sharp and contrasted for me so much so often I even need to pull it back a little so I don’t work too hard initially to really bump contrast/detail until I see what that does first…

There will be documentation as there is for all items and for sure the release blog post will have an entry. Technically it has just been merged so it is in testing. You can fairly rapidly scroll the 700 post thread and see where the image clusters and descriptions are…Filmic has been a very difficult module to get people to grasp and it has evolved and matured. I suspect that there will be some progression in the same way with Sigmoid but its simple and not trying to do too many things so I think it will be a much easier sell… I think in the link I provided above there are selected links provided to target most questions so if its not enough to learn it via self discovery there are definitely already some pointers to some basic information…

Great. Thanks

It really is all summarized pretty nicely here just incase you didn’t peek at it…

I did…

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@jandren will there?

There curves tool that runs in a browser is really cool…you can compare filmic with sigmoid. Adjust the parameters and even compare to blender and other curve models…

At the very least it is a quick visual answer to Terry and and Tony wrt what do the parameters do… from a tone perspective…

https://jandren-tone-curve-explorer-streamlit-app-xca32q.streamlit.app/

The 12642 PR is a pretty good start …just needs some between the lines and some formatting to fit into the DT manual format…

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Well volunteered

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Both Filmic and Sigmoid are tone-mappers. Their job is to map the linear, scene-referred data to non-linear, display-referred data that your monitor (or print medium) can display correctly. They just do it in slightly different ways, providing different trade-offs.

Since it makes no sense to tone-map twice, only one tone-mapping module should ever be active.

If you don’t understand the scene-referred workflow and the role tone-mappers such as Filmic and Sigmoid play, I highly recommend the following:

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Thanks. Useful. I “understand” filmic