A really tricky one, because there are many directions to go.
I didn’t keep the colours from the right-side windows, but instead emphasized the flags (dodging, increasing the saturation and a bit of a hue shift) a bit more in an attempt to guide the viewer’s eye forward along the flags towards the end window. There is a lot going on in the image so that I feel like a decision needs to be made what to show.
Darktable sidecar: 20230317_0001.RW2.xmp (108.6 KB)
From what I remember, yours and @Terry have the most natural colours in the facing stained glass window. The reds, in particular, aren’t as heavily saturated as my efforts and more detail is retained.
A great, contrasty rendition, without losing shadow details. Congratulations!
I also think that we want to see the flags.
Too bad the stain-glasses are clipped but I know it is very difficult to avoid it in such places.
This is closer to my first effort, not posted, but again you’ve done way better than me with the clipped window. I only realised the huge dynamic range in there when I tried to use the camera as our eyes seamlessly adjust. I should have exposed for the highlights.
Thanks for the play 
Here is my experiment, concentraing on one RawTherapee module:
Local adjustments/Log encoding. Very powerful [especially if you have studied Rawpedia]!
Have fun!
Claes in Lund, Sweden
This one’s from the movie. Like it a lot. Not afraid to lose details in the shadows in exchange for drama. Sometimes I think I avoid losing detail just because the camera has managed to capture it, rather than because it adds anything to the picture. A smaller dynamic range would force me to choose what to emphasise.
That is what I like about the playraw category and why I learn so much from it. But sometimes my edits as I see them on my screen do not translate correctly when posted. I like the way @kofa has applied a similar masking techniques as me but has instead used it with the colour balance module to add colorfullness. Nicely done and why I love that module so much.
I like how you have chosen the flags as the priority in the image. It is very effective and a differnt take on the same scene. Nicely done.
I have tried to preserve the intimate atmosphere of the interior of the Cathedral, as well as the shades of white of the flags and the colorful stained glass windows. Keeping in mind that the main light comes from the right.
20230316_0083.RW2.xmp (22,0 KB)
Have fun!
Nice. I found keeping the flags white difficult
I think most of you are missing the obvious and it is far too busy with no real subject. I do not get it. So maybe think firstly of cropping.
I believe cropping is the most important first step.
The half window and top of arched door on the left is far too distracting and needs a good crop and also from the top cutting out the ceiling. This brings the flags as the subject with the nice colour reflections on the background wall.
I did this on your photo just with blanking of the things mentioned with holding two sheets of paper against the screen and straight away could see the potential improvement.
You can then concentrate on making the flags pop.
Maybe change perspective when shooting, move around, zoom in and out. Take plenty of shots.
Feel free to upload your version.
Good point. The problem is the photo. @Terry makes the point higher up about pre-visualising the shot. Whereas what happened was I took a shot of the flags, later the light flooded in, I thought, ‘ooh, pretty colours’, and went back and took it again. It’s only through editing and then seeing others’ efforts that I can fully see the problem. Having said that, I can see that people have made much better stabs at isolating a key element than I did.
Obviously, I took other shots but I found the wide dynamic range and dim interiors in the cathedral difficult and they all have problems. These are the ones I kept from that day.
Yes the three flags and window is much better. Less cluttered, less confusing. You could almost experiment with masks to make a low key photo making the window pop more with the surroundings and flags in shadow?
Could possibly do in DT but I would tend to work in GIMP for this one so you can use layers.
