Because many continue to have difficulties with channel mixer, I decided to bring it up again with the hope that it might make it easier to understand.
In this episode I also took a couple of raw files from our play-raw category:
Thank you @s7habo for this very clear explanation of the channel mixer (with practical examples too). This really helped me and I now feel like I have a better understanding of how it works and how to apply it with my photos
Thanks for this very clear episode.
There is just one point which I didnāt fully understand, when you set the red and green channel to zero (at about 5 minutes) and add input red/green in the blue channel. Isnāt it just a multiplication of the blue values with the values of red or green in the same pixel. But if the red or green values are set to zero why do you get positive blue values in these areas, shouldnāt they remain black (multiplication by zero)? Must probably be a more complex operation?
Thanks, itās an addition in proportion of the percentage of the input channel. Also, when you set red/green to zero, then the output is set to zero, i.e. black, but the input values are still there and those are used for calculating the new output value.
Thanks Boris, I think I finally get it. Now I need to practice this on my own photos.
The way you analyse the colors in a photo and have a clear vision of what look you want the final image to have is something I have to improve on as well. The changes you make seem very subtle but in the end it surprises me how much it improves the photo.
Thanks for all the time you spend making these videos!
Hello Boris,
thanks for your videos and your tremendous activities. Iāve learnd so much about photo editing from you. Itās always a pleasure.
But now I have a problem. in the last weeks I selected my photos Iāve taken in holydays. And now I want to edĆt them for a little book. But in the meantime Iāve watched your videos about color harmonies an I am excited. And now Iām hooked.
But so it takes a long more time to edit my photos. But without the color harmonies, Iām no longer satiesfied with the pictures. But whatās the solution therefor?
The solution will be to edit more and more photos and to understand to work with channel mixer and how it works.
By the way I have found an articel about adjusting color with channel mixer also based on your and Nicolas Winspeare videos. I think this can also help to understand an to achieve the desired results. The artice is in german language but nowadays itās no problem to translate within the browser in several languages.
So, these were my thoughts in the last days. Hope you will go on to take me on the editing tour even though itās stressfull (for me). Once again, thanks!
Thomas
I am probably stupid, but is there a text tutorial on this stuff, anywhere? I canāt always tell what Boris is doing in the videos. He says what heās doing, clicks somewhere, and magic happens. I canāt tell what he clicked on to do that. Iām not a video learner; Iād rather have written instructions.
I can display the vectorscope, but then I do not see how he gets the complementary colors controls (the pie shapes that cross in the middle) to even open. I have read the vectorscope sections in the documentation, and they donāt even seem to mention it.
In short, I canāt get past square one in trying to use color harmonies. I will try to watch the first video again, but I would profit more from some readable instructions.
Iāve been writing some text-based tutorials here. I have plans to do more, but am limited on time. The most recent one, Changing Colors, covers some of this material with the channel mixer but nowhere near the level of depth as these video tutorials.
Thank you. I figured that out after rewatching the first video in the series. I figured out how to map the color points, too.
Now, I just have to figure out how to know what to do with them. I think in Borisās second example, he changed the hanging leaves from a maroon color to burnt red. I donāt think I would ever have such an idea. I donāt know why Boris had such an idea, although the end result looked great.
The vectorscope display I got on my first attempt did not fit the complementary configuration, either. So I will need to watch more of his examples to see how to deal with images like that.
I guess I just need a lot more time to digest all of this.
I would not, either. I donāt colour grade my photos, I use pretty straight-forward processing most of the time (two diffuse or sharpen instances, one with the local contrast, the other with the sharpen demosaicing AA filter preset; color balance rgb with the basic colorfulness: standard preset; filmic rgb or sigmoid and finally local contrast). I donāt actually think all photos need to be graded, or that one always has to bend a photo to match one of the āharmoniesā. I understand that for fashion/glamour/product photography, itās a useful tool, but I mostly shoot landscapes, and if a flower is almost, but not exactly opposite the sky on the vectorscope, I wonāt line them up just to boost visual contrast.
Same here more or less, landscapes, too. Iāll spot-adjust tone, hue and saturation but overall color grading is usually limited to cooling shadows and warming highlights mostly. Of course part of the reason I say / do that is because my processing skills are pretty limited. Maybe thatās kinda like a guitarist saying, āI just play one note solos because thatās what I feel, man!ā, when the truth is, thatās all he can playā¦
Yes, I agree, trying to bend colours in landscapes to match colour harmony rules can yield some strange results but perhaps that is just in my incapable hands! Sometimes it works to achieve a stylised result for the right scene thoughā¦
I think the new primaries tool will be useful in landscapes to sort or shift foliage and other aspects esp to contract or expand the range of colorsā¦ There may not be that much in the way of videos specific to DT but Adobe has a feature they call camera calibration that I believe essentially does a very similar edit on the image and there are quite a few videoās out there on uses of it and examples of how you might apply itā¦
Yes looking at Boris video, primaries looks like a really useful time saving tool that is easy to get your head round. Itās been available in ART for a while too.
Niceā¦ I just mentioned Adobe as there are videos with scenarios and examples to apply such a toolā¦ it wasnāt meant as a slight to any FOSS stuff for sureā¦.
I tried very hard to get my head around to using the channel mixer Borisās way, and although
I get the theory behind it, I am enable to do so. And my age doesnāt help. ( I am 78). But I am very happy about the new primaries tool, very promising, so I will leave it to that. (The 80/20 Rule).
I think in Borisās second example, he changed the hanging leaves from a maroon color to burnt red. I donāt think I would ever have such an idea. I donāt know why Boris had such an idea, although the end result looked great.
Maybe thatās kinda like a guitarist saying, āI just play one note solos because thatās what I feel, man!ā, when the truth is, thatās all he can playā¦ 
