[Play Raw] Mo and better blending?

play_raw
darktable
siril
gimp

(Gustavo Adolfo) #1

Hi, I wonder if you guys could give a better solution to blending these two images I shot some time ago.

The sky portion comes from Siril, and the foreground from median stacking on gimp.

Below is the end result I got. I’m still not completely satisfied regarding the blending, for one reason: the appearance of subtle horizontal bands in the horizon, where the sky meets the ground. I double checked the raws and there’s no banding there. I don’t want to get rid completely of the pollution and mist, since it was part of the scene, and I think it gives a more realistic feeling. I just want to get rid of the bands, but so far no success. I suspect the bands originate from the blending in gimp, more exactly, from the gradient tool.

Siril output, Siril extracted background and gimp foreground: https://drive.google.com/open?id=1bjzY_zu3CCpiSlzxNhG4EvumFTLJjkMX

Thanks to @Jonas_Wagner for the tip on extracting the background. I just didn’t do it the way he puts it because this Siril version allows to do it already, and easily.


(Jonas Wagner) #2

Hey @gadolf

This is a really late reply. I can’t see any clear banding on my screen (maybe I need to recalibrate) but try dithering. Dithering the gradient, heavy dithering when going from 16 bit to 8 bit etc. That usually limits the banding. But in the end 8 bit just isn’t really enough - there will always be some blanding.


(Sebastien Guyader) #3

Another late reply, since I missed this thread…
I’ve been into Siril these days. For the foreground, I also used Siril for stacking, this way I was sure to have both the sky and the foreground being processed the same way (instead of median stacking, I use Average with pixel rejection, which is supposed to be better, according to the Siril tooltip). The only difference is that for the foreground, I skipped the registering part. In the end I have 2 images with the same pre- and post-processing (except for alignment on stars), that I can easily blend in Gimp.


(Gustavo Adolfo) #4

@Jonas_Wagner Thanks for the feedback and for having showed me Siril existence (from an old post from yours). One of the things that kept me from getting rid of Windows was that I used DeepSkyStacker, but Siril seems to be a good replacement - not so complete, but almost. When I have the time, I’ll review my workflow and see if I can improve things.

@sguyader Thanks for reporting your workflow. I saw your recent post (a beautiful nightscape!). Interesting approach using Siril for both background and foreground. Next time I try one of these again, I’ll do that.


(Pat David) #5

I haven’t had a chance to try Siril yet personally - anyone feeling up for creating a tutorial possibly?

It might be neat to learn, and we have a shot to practice with! :slight_smile:


(Sebastien Guyader) #6

I don’t know if I can write a good. I used Siril, but I’m not sure I understand everything under the hood.
But I can try writing a tutorial if nobody else feels like doing it.
I can also share publicly the raw files I used last time for this showcase.


(Mica) #7

I’d be happy to test, edit, and question any tutorial.


(Sebastien Guyader) #8

I started preparing a tutorial for Siril. It’s going to take me awhile to to finish it, as I don’t have much spare time these days.