Ever since I started using darktable, my workflow’s been looking like
technical adjustments (lens correction, denoise, exposure, color balance rgb)
tone mapper adjustments (one of AgX, filmic, sigmoid)
creative adjustment (diffuse or sharpen, tone equalizer, color grading, additional exposure modules for doging and burning)
I’m probably overthinking this, but my issue here is, there is uually a tone mapper with default values enabled from start, or if it isn’t, that’s probably even worse as the image is basically broken.
So my questions are:
how does your workflow enable you to properly judge exposure?
strictly technically speaking, is there an issue with readjusting exposure after setting the tone mapper to your taste? (since it relies on identifying black and white which the exposure will inevitable change)
Basically, with exposure you set the midtones, the tonemapper is there to take care of the shadows, and esp. the highlights. And most tone mappers leave the mid tones alone (except for the contrast adjustment).
So adjusting exposure before setting the tone mapper works just fine (and is actually the “recommended” order). Most of the other operations you mention are either purely technical, or can also be judged on the mid tones.
Not true: if your image has a fairly low dynamic range, you may not even need a tone mapper. Examples could be still life scenes with one illuminant and mainly diffuse reflections.
And when you use a tone mapper, you may indeed have to adjust the tonemapper when you adjust the exposure. And that’s just fine. It just can get tricky if you rely on automatic settings for exposure and tone mapper (as those are set when the module is activated, or you request it).
Note that not only adjustments to the exposure module may force you to adjust the tone mapper. E.g. tone equaliser can have the same effect (as you can adjust the whites and blacks). Same with dodging and burning.
What do you mean by that? What qualifies an improperly judged exposure?
All modern tone mappers map mid grey to mid grey so I orient setting the exposure by the mid-tones and manage highlights and shadows from there with the tonemappers settings/cbrgb/tone equalizer/shadows and highlights/local contrast.
I have listened and learned on the forum. Previously I used to take care of the highlights in the exposure module and then recover shadows. It worked well for me. However, I became convinced that the suggested pathway of using exposure to set the midtones and then let the tone mapper do the heavy lifting for the shadow and highlights is possibly a better approach.
To this end I have started using the RGB parade for scopes as I personally can visualise the placement of midtones better with this scope than other options. Of course I still rely on my eye to judge the exposure on the picture itself.
I also find that AgX has made my life much easier when using modules like tone equalizer to recover highlights or shadows. AgX seems to recover the contrast that can be lost with brightening shadows and darkening highlights in the tone equalizer or RGB color balance modules.
Just my 2 cents worth.
I have found my final tweak of exposure (brightness) I make with the pivot target output slider of AgX. It is often the very last step I return to in my edit when I look at the finished edit and feel it needs a small brightness tweak. This is one of my favourite features of AgX besides the auto tune levels option that works so reliably for me.
Here’s a tip. Setting exposure is usually quite hard with the low contrast default settings of the tone mappers in darktable. The lower the contrast is, the harder it gets.
Dial up the tone mapper contrast way beyond what looks good.
Dial in the exposure.
Lower the tone mapper contrast to what looks good.
In addition to all above - just switch the tone-mapper on and off a couple of times and see what happens. How you react may be an indication of the direction you might take developing your picture (other modules may benefit from this too).
I had fallen into the habit of having my default workflow being “scene-referred (sigmoid)”, but with the advent of AgX, I switched to no default tone-mapper. I discovered that a lot of my lower contrast images “came alive” with no tone mapper, especially in the highlights.
That’s not surprising, since default AgX settings might mitigate highlights that doesn’t need to be mitigated. Proper setting of the input exposure range (at least the white point) can give a better starting point - you need to adjust that later if you increased highlights by using exposure or toneequalize during editing …
There’s no point, as those new presets as close to sigmoid, so if an image does not benefit from the sigmoid curve, it won’t benefit from its clone, either.
