@gadolf In Sweden we have a saying: There are many ways to skin a cat. Evidently, we can adopt the same proverb to dehazing an image…
So far, dehaze, equalizer and filmic modules have been used. Hm… any other modules that might be of use?
The ability to stack several instances is very powerful 
Have fun!
Claes in Lund, Sweden
There are no mice in Sweden??
@Claes very colorful saying, I like it. But here in Russia we say: No matter what (and how) you do during first wedding night, only one (good) result is expected of you 
— haze removal is expected to remove haze )))
@gadolf, I’m not sure that second instance of your tone curve module can be considered as haze removal ))) It brings back some details in sky but reduced contrast in shadows remains the same. Nevertheless I do mostly the same way (with parametric mask) and tone curve settings like this:
But it requires a lot of fiddling with sliders of parametric mask 
I’m not either, but since I came to this post from @shreedhar, I started to use the LAB lightness curve to remove haze instead of the haze removal tool, which I find too aggressive. Then, after the filmic tool arrival and its underlying theory about keeping the RGB proportions unchanged, I started to use an RGB curve instead of LAB, for that purpose.
PS: I’m delighted to learn about northern cultures through their sayings 
My take on this.
My take using RawTherapee:
I ca corrected, dual demosaiced and so on
Edit: view at 100%
First in Filmulator1.0β
In RT 5.5, I used the LAB module, Haze removal module and Final Touch Up module together with edge sharpness of Wavelets to get this.
_DSC0653.jpg.out.pp3 (12.0 KB)
EDIT: The photo was flat in lighting, colors were washed out and there was haze. Hence, used L, A, B curves to set the colors right (according to my monitor), the rest is to remove the haze and add contrast.
EDIT 2: I forgot to add that on top of what I did, you can also use local contrast module to further remove the haze (experiment with high radius and low amount) but it looked a bit artificial to me.
Hi all,
Hm. The results so far are still too hazy.
There are some windmills on the mountrain ridge
far, far back in the upper right part of the image.
Quest: How many windmills are there?
Have fun!
Claes in Lund, Sweden
I do not want to be problematic (just a little), but could we have them de-hazed?
I may be wrong - but I do not see 11 windmills. But of course, your monitor could be better than mine 
Have fun!
Claes in Lund, Sweden
There you go
(I think I’m cheating 
…)
DISCLAIMER: I took a printscreen from darktable zoomed at that area (very bright), pasted it on Gimp, exported to tif, opened it on DT, and applied filmic (auto tune, then tweaked black relative exposure)
Good evening, @gadolf,
No, I do not think that you cheated – more or less any method would be OK in order to reach the correct answer.
BUT: You forget to answer the question!!! How many windmills are there?
Have fun!
Claes in Lund, Sweden
10?
That is what I also think
But the 11th, which Tamur found, might,
perhaps, be there as well (number 3 from
left in his foggy image).
Have fun!
Claes in Lund, Sweden
Sidenote: Nothing against gimp, on the contrary, but I didn’t need to take a so complicated tour. I could have used the very easy duplicate manager from DT to make a copy, then crop it and apply the same filmic I did before… anyway…
RawTherapee (shamefully not upgraded to latest - so no dehaze tool for me!)
Mainly the graduated filter and a very custom tone curve, plus a bit of tone mapping to add back some local contrast.
