@Joanna , can you post a copy in colour and say something about light and exposure?
At 25k settings, your camera has a dynamic range of about 6 to 7 stops according to dxomark.com and getting the outside through the window means that the room was relatively well lit…or the dynamic range of the scene would have been too wide to capture.
The photo was taken at 18h41, so the light outside was already starting to fade. It was dull and cloudy and what you can see of the outside is a small enclosed courtyard.
Inside, there were a few small suspended ceiling spots.
As usual, I shot at 5600°K and changed the colour temperature to 4382°K in PL.
Exposure was 1/1250sec @ f/5.6, spot measured at +1EV from the reflection on the wing of the chair.
As you can see from above, it was the inverse - the outside was poorly lit 
yes…and that’s why I put in “relatively” as in “relative to the light outside” 
1/1250! @ f/5.6 
and spotmetering to the least important part (for me) of the image. Interesting. These professionals have ideas… 
Indeed. f/5.6 to reduce the depth of field and 1/1250 to avoid movement blur.
But the most important in terms of not blowing the highlight
That’s what we’re paid for
I’m intrigued:
f5.6 to reduce the depth of field: Surely to reduce the depth of field, and with low light then you could have gone even wider than this. f4 and f2.8 being entirely feasible too, and allowing you to bring the ISO down a stop or two. It’s your image, so I’m interested in what aspects you wished to highlight with the subject and scene.
1/1250 to avoid movement blur? This seems very fast for a person sitting (imo). Unless you wished to freeze the hand movements too? But hand movement (especially for the hand strumming the strings) could have been a nice artistic touch (similar to panning a shot of car adds movement and dynamicism to the image). Again, not being critical, it’s a nice image, but I am interested in your thought process for the photo. Again, further options here to bring the ISO down another stop or two.
Also, I’m interested to know why you chose not to use flash to light the subject.
The power of DeepPrime NR (regular and XD) really is staggering, isn’t it?
Never doubted that.
And it’s a mere coincidence that today DxO just announced the power of noise reduction for PureRaw3, of course. “The essential workflow companion for incredible noise reduction”
So, I’m implying another coincidence with
I’m kiddin’ 
but you know, as you deleted all EXIF data from the file, we just have to trust you with the ISO and every other data you just gave. I’m guessing you were using your “always on camera” 24-120/4 Nikkor, so just had to stop down 1 stop?
And I have to say, Joanna, the sharpness leave something to be desired. It’s well focused and still not pin-sharp. So, if my guess with the lens was right… ok, it was a guess and I don’t want to conclude about guesswork. I was just looking for images with f/5.6, ISO 25.600, and fast shutter speed. But since I’m not a pro with ideas (pun intended), I’m hesitative with cranking ISO and shutterspeed and closing apertures. Here’s one of the 7 out of nearly 35k. And I consider it as the sharpness I’m used to and expecting, and honestly I don’t care about noise at all.
And this one’s shot at 200 mm f/2.8, ISO 25.600 and 1/6500
Okay, your post was about to give a “big shout for DeepPrime XD” and I don’t want to diminish the noise reduction. But again, noise is to me the least important quality of an image. “Sharp”, “well-exposed” and “well-focused” rank so much higher.
Not if I wanted to keep both the face and the banjo in focus. And the lens was the Nikon 28-300mm, with only f/3.5 at 28mm - this was taken at 65mm.
But why bother if DPXD makes it possible at the ISO I chose?
But it is what I desired, slightly soft and gentle. LF portait photography puts great store on soft lenses as an artistic device.
Since when is a D850 considered a LF camera? Horses for courses, in my opinion a “soft and artistic lens” doesn’t make a normal picture a LF one but looks technically a bit poor. Again, only my opinion.
It would be very difficult to take an LF image of a strumming banjo player. By trying to imitate “artistic devices” of a camera the D850 is definitely not you’re doing yourself no favor. But others will have a different idea about that. Else I also could add a bit blurr to my images and change the camera brand’s name in EXIF to Leica, preferably the one Mike Myers i.e. use so artistically (= blurred). Joanna, the world is already full of fake. Declaring a technical weakness to artistically LF, sorry, there are no nice words I can say about that.
I suppose that you’re not saying that your D850 is LF, but that you tried to make your image look like if it was taken with a LF portrait lens
Well, not really. More that I reacted to this insane obsession with images always having to be hyper-sharp. I didn’t do anything intentional to make the image soft. But I like it like it is, possibly because it reminds me of what older, softer lenses can give to an image.
I make a difference between hyper sharp and sharp. Where hyper sharp = oversharpened.
But using a 135 format camera capable of rather sharp (not hyper sharp, for that you had to use a D800E) to create soft images reminding of very old lenses on a LF camera… where’s the difference to using a smartphone and banging a filter on an image? It’s just a question, not a start for a crusade.
Does XD work with Fuji raw files yet?
20 minutes to export 1 picture on a macbook air (intel). Hopefully it’s faster on apple silicon.
10 minutes would be “faster” than 20, but… 
how much MP has the RAW?
That seems very slow. My old Win 10 machine, when using only on-board Intel graphics, takes only 4-5 mins to export a 30 MB Canon .CR3 file to a TIFF. Using a low spec graphics card (GTX 1050 ti) brings the export time down to about 30 seconds.
What sort of graphics card is in your machine?
Probably the best lesson of this discussion 
It’s around 18-25s per image (24Mp raw) exported using DeepPrime XD as high res jpg on my M1 Mac Mini.
It is about 8-10s per image if I use regular DeepPrime.
26 megapixels
