I got G'Mic to work on my windows machine. Yeh! So i am following all your steps so far.

Good for you. Check out the XCF file that shared the link if you don't want to wait on my slo-mo tut. lol

I hate doing tuts; I do so many nuiance steps that tuts by me should only be used as a guide anyway. I play by the seat of my pants when I play and forget how I do stuff often enough. lolol

I do not know if it's a fake or not HDR, but following the technique of convolution exposed by lylejk my result is as follows, but with an addition. This totally made ​​G'mic.

First:
Open the pic, duplicate it.
Second:
G'mic, input mode (default), output (new layer), repair → bilateral (smooth): default values except channel, set luminance.
Third:
G'mic, input mode (default and lower), output (default), layers → blend (standard) → grain extract
Fourth:
G'mic, input mode (default), output (new layer), layers → blend (standard) → grain merge
Fifth:
G'mic, input mode (default), output (new layer), details → tone mapping (0.20, 0.75, 0, 16, 3=luminance, 0)

Original pic

Big fan of the Dave Hill like result jamac4k. Haven't decided if I will finish the Fake HDR tut today or not (hope you all can take the suspense; lol).

OK; just finalizing the tut; any additional tweaks are up to you (I already mentioned suggestions). I don't document nuance. lol





Result:

Also, forgot to mention that I had to reduce the blue channel since it was too strong in the shadows (because of the image used). This really is part of the nuance but felt I had to share this tidbit with you.

what are those grey visible layers?

Dup, bilateral (g'mic) filter result set to Grain Extract 2-ton. The gray like layer is called a convolution layer (thing Highpass filter). Set to Grain merge, it amplifies the change each time you duplicate the layer.

thanks for clearing that up…makes sense now!

I'm working on a way to eliminate the skyline with the sky/landscape border using the technique outlined. Notice that the images I used has no sky (reason is because of a black skyline issue; again, I believe I have a solution but the solution is not an automated one so reluctant to share; it involves the running the erode filter, copying visible, then undoing the erode filter and then pasting what you copied and reducing the opacity to between 20% and 25% and erasing the landscape part). The solution I believe I found is convoluted (I know; a pun; lol) to say the least.