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An AgX version from Kofa’s new Darktable build.
It’s a little overdone for my liking, but I wanted to experiment with a dramatic look.
IMG_7730_02.cr2.xmp (14.6 KB)
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Hey guys, you’re great! I’m glad you like the picture. And it’s very interesting to see how different the edits turn out. Sometimes a little flatter, more natural, less saturation and a plain sky. But sometimes really saturated colors with great contrasts and a lot of drama in the picture.
It’s like some of you have written: You can take this photo in many different directions.
@Popanz Why did you use the base curve for your processing?
I ask because I still have a little trouble with the whole display and screen-related workflow. I’ve been using the scene-based workflow for a while now, but somehow it hasn’t become second nature to me yet.
I really like this category because you can see how differently an image can be edited. It helps me to find my own style. To see what I like and what I don’t like so much. Thank you very much for editing and developing!
And: what is AgX?
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AgX is shorthand for silver based photo, Silver halide - Wikipedia, and here it more specifically relates to various algorithms seeking to emulate the behavior of film in the way it reacts to exposure (like what has been the basis for e.g. filmic modules).
Currently there are two projects going on her with AgX relevance:
kofa’s test development of a module implementing in darktable an algorithm used in Blender:
(There is also some kind of AgX-implementation in ART)
Then there is another project where one does a complete simulation of all the chemistry/physics in film based photography / image processing.
EDIT: Where in Norway is the picture taken?
The basecurve for some time has been moved to the same point in the pipeline as the other tonemappers. If you don’t need to manage an image with a really HDR then it can often give very nice results…in the past it was a true display referred module as I think it came in the pipeline before the input profile…if you experiment you can check by just using the legacy module order found lower right in darkroom view… this will show the impact of that shift… so unlike the others it will expect you to manage DNR going in to it but its at the end of most of the processing so not introducing a nonlinear mapping before the other modules…
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Seeing that it’s what people seem to prefer, I have kicked up my edit, a bit. I was trying to keep it looking natural in my first edit.
IMG_7730_01.cr2.xmp (12.6 KB)
Because I can 
Sorry for joking. The answer is here:
At the moment, I have not yet decided what will be my standard tone mapper. For a long time it was sigmoid and there are good chances, that it will be for a while longer. On the other hand I rediscovered the charm of the base curve. Even so it doesn’t work equally well with all pictures, especially when it comes to the handling of really high dynamic ranges.
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I know exactly what you mean, but I miss the ability to use a colour picker and choose the exact spot on the spline. RGB curve has this feature. Incidentally, other than camera JPEG presets, is there any reason to choose Base Curve over RGB Curve, or can they pretty much be used interchangeably?
In theory, Tone Equalizer offers the precise control over the curve that Base Curve does, but it’s just not as easy. I do enjoy adding a node to the curve in Base Curve/RGB Curve, and just being able to drag it up/down/left/right and seeing the real-time effect on the image. Tone EQ is just so much more fiddly, and I really don’t like not knowing exactly where my black/white points are.
Well, the time was 18:30 and it was still early October.
A little dependent on your latitude, though, but I feel my general experience of autumn in Norway leads to this:
IMG_7730.cr2.xmp (12.5 . KB)
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I’m submitting this version just to show how decreasing the dynamic range with Tone Equalizer and then creating a curve with RGB Curve can get you to a really nice starting point. Notice how few modules I’ve activated on the right. Everything is at default, and then I just added Tone Equalizer and RGB Curve:
I’m very impressed with how quick this was.
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I’m unfortunately a noob regarding the theories behind the modules. There are three curve modules. Base curve, tone curve RGB curve. I don’t really got the differences between this modules. I know, that the handling of high dynamics in tone curve and base curve is differently. See here:
I can confirm there are differences and tone curve doesn’t work to well on really high dynamic range pictures.
Maybe someone can give us more insight on the RGB curve.
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@Popanz, yeah, I’ve read the manual about all these different modules, but it doesn’t really say much about the pros and cons, when to use and not to use.
I don’t use Tone Curve at all because it’s been replaced by RGB Curve in the scene-referred workflow. And my understanding is that RGB Curve is not meant as a tone mapper at all. The idea is probably that you would use Base Curve as the tone mapper, and then just do contrast tweaks with RGB Curve like you would in other RAW developers like Lightroom.
But I’m just wondering if functionally they are any different. I seem to get similar results with them. I’ve only just started experimenting with them recently because I always thought of them as non-recommended modules. But they are easy to use, and that’s always a win. I’m mostly a Sigmoid guy, but it’s lacking fine control in certain areas. AgX promises to solve some of those issues, although I’m finding the recent builds less easy to use.
I agree with all your points here.
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You should do what pleases you @Tim ! I’m not sure if there’s a general preference here or not, but I enjoy looking at everyone’s interpretations. Also, my submissions don’t always reflect my preferences. Sometimes I just use the picture to experiment with looks or practice with certain modules. I generally prefer natural edits to ones that stereotypically “pop”, but I’ve noticed that the latter definitely get more likes on Pixelfed where I post some of my work.
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Again very generically the old module works in LAB and the new one is using RGB wrt the tone curves… The basecurves are generated from jpg/raw pairs the process and some details are here… I think 20-50 is suggested as a good number shot in varying conditions.
When you look at the input and outputs the difference in the tip says that the output of the rgb tone curve is linear and the basecurve is not… its easy enough to put them both in the same spot in the pipeline and blend in difference and see if you get much difference…no pun intended… the base curve values are 1 to 100 percent so to mimic them on the tone curve you need to do a little math but its generally only about 5 points I think…I don’t know if specifying just the same 5 points gets you more or less the same curve or it will deviate a bit here and there…
I just use my eyes more and more these days and quickly test approaches …
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As far as I remember, there was a bit more red in the whole scene - that impressed me. I live in the Alps and I’m used to a lot when it comes to autumn colors and moods. But I’ve never seen anything as intense as there in Voss/Aurland.
If I understand correctly, you are not using the scene-referred workflow here? At least I can’t see Filmic or Sigmoid anywhere. Do you have the .xmp file for this version so that I can have a look at it directly in DT?
Sure, although I messed with it a bit since posting the screenshot so not sure if it’s exactly the same.
It’s actually mainly scene-referred but RGB Curve is acting as the tone mapper, and it works in display-referred space. So it’s pretty much like using Base Curve instead of Sigmoid / Filmic RGB.
IMG_7730_03.cr2.xmp (10.4 KB)
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