Hey all - I am doing a weekly photo challenge, and this week is B&W. I have a few I’m happy with, but I was curious if anyone wanted to show me how they would see this photo in B&W. Here is what I came up with.
2025-03-06_Mar At Home_64.CR2 (19.0 MB)
2025-03-06_Mar At Home_64.CR2.xmp (14.2 KB)
This file is licensed Creative Commons, By-Attribution, Share-Alike.
Your own rendering is nice to have, but not mandatory. If you are having some specific problem, state that too.
I like monochrome-ing, brings back fond darkroom memories…
Here’s my take, grayscaled using the red and blue channels at full-tilt. That negated the need for any tone curve:
Oh that’s neat 
I like the lighter petals - I got kind of stuck on what I had but this looks good too.
2025-03-06_Mar At Home_64.CR2.xmp (22.8 KB)
dt 5.1
I haven’t done any monochrome in darktable yet but I do enjoy taking monochrome flower photos. In Lightroom I would just use my camera’s monochrome profile as a starting point, for better or worse, and I never really explored outside of that option. Of the monochrome flowers that I’ve done I tend to like ones where the flower is somewhat uniform mid/highlight tone. It kind of mimics an infrared monochrome look sometimes. That didn’t always work out with every flower though.
Since dartkable doesn’t really have an opinionated view on monochrome (aside from offering some B&W film presets), I didn’t know how to approach this. I basically ended up moving the RGB sliders until I found a result I liked. But my brain is really looking for the “correct” result which I’m guessing probably doesn’t exist either in darktable or digital monochrome in general.
Am I correct that the “normalize channels” checkbox in color calibration basically just limits the output to 100%? In other words, setting red and green to 100% would really be 50% each? It seems like setting all the channels to 100% and unchecking that box is like bumping the exposure by 1-2 stops or something like that.
Anyways, this was a fun one to try real quick as I haven’t taken any flower photos in quite some time. I do enjoy your original, @MattInWA!
First attempt at toning. I stuggled…and still failed…to get the colors right. Fun nonetheless! Thanks!
2025-03-06_Mar At Home_64.CR2.xmp (24,5 KB)
Really nice contrast!
2025-03-06_Mar At Home_64.CR2.arp (13.7 KB)
I like the nearly black background here
Thanks! Glad to see people are trying it out!
I had to look it up because I was curious about this. Here’s what the manual says for the gray tab controls:
Select this checkbox to try to keep the overall brightness constant as the sliders are adjusted.
So, not clear to me if it would mix them 50/50, but that would make sense I guess.
With these conversions, I have sliders for each of the R,G, and B channels for mixing things up. I tend to just slide them around until the image looks interesting. For this one, I ended up with the R and B sliders all the way to max, and G at 0:
No technique, no math, just messing around… 
