Here is a photo I took of a flower in the garden. Very sunny day, no clouds, 2pm. In camera white balance set to auto. It looks very yellow/green (which makes sense considering the content) and I just cannot adjust the white balance in darktable to make it look somewhat normal. The other photos I took, in the same garden, at the same time, look good with just a small tweak of the temperature slider.
I know “normal” is subjective, in this instance I really do mean somewhat normal to the naked eye, without the overly yellow/green tint that it seems to have.
Would be interested to see how others would white balance this.
(The attached file is licensed under the Creative Commons license CC0. You are free to do with it whatever you wish)
Regarding the license to use, we generally use Creative Commons licenses. You just say in your post that the attached file is licensed under one of these licenses. Here is a link to way more than you may want to know:
I am unsure what normal is for this photo. However, I looked at the image using sigmoid and again using filmic V5 with no chrominance preservation. The result was significantly different. Maybe the tone mapper used (filmic or sigmoid) is the source of your difficulty because white balance only does so much. Which are you using? Can you share your xmp file?
There is a lot of bounce light there. You can often just use the global auto picker in the CC module. This will do its job and make things neutral but the result might not look good… Just try pulling back the chroma slider of the CC adjustment. Do it slowly and reintroduce the cast in the original light ever so slightly… Sometimes that is a good look… if not the channel mixer is a good tool to tweak those greens
There’s not really a 'correct WB for this, as the flower is evidently lit by green light filtering through or bouncing off surrounding plants… and if you correct for that, the background in sunlight will go a bit weird.
I’d do something like this… DSC_0022.NEF.xmp (14.3 KB)
The flower is amongst all the greenery, I never thought about the fact that this makes the flower lit by green bounce light. That might be a light bulb moment for me. I still struggle with the concept that in real life, my brain does an amazing job with colour.
Regarding the CC module, I do find that the auto picker often makes my colours look wierd. Is that just what happens when it neutralises colours? I am then meant to re-introduce the colour cast? I might have given up on CC auto picker to easily, I will definately revisit it.
Is it OK to upload 1 more photo from the same garden, same day? I find it even more difficult and wonder if you will use the same techniques. Meanwhile, I am going to reset my edit and have another go with CC, also going to look at custom chroma and hue instead of just using temperature.
Pretty much… in an ideal world, you would always have a grey card, or something neutral, in each shot. But without that, the CC picker can only make a guess at what should be neutral and in a very mixed situation like your flower shot it won’t always get it right.
Depending on the subject I often either start with the ‘as shot’ and tweak from there (switching to ‘custom’ to get the illuminant and chroma sliders if need be) or autopick, then tweak.
You certainly can let it do it’s best effort at removing any cast, then reintroduce any colour you want (rgb primary’s tint slider is the simplest choice for this IMO but colour balance rgb can do it too).
But in many situations I find it’s quicker to just tune CC to get the approximate colours I want in the first place.
This was tough, and its a problem that I encounter a lot when I’m shooting under foliage. I think one issue is that there’s direct sunlight in the background, so you have two sources of illumination. Here’s my attempt:
I applied two instances of color calibration, the first to get the flower and foliage as close as I could imagine, and then a second that was masked for the blue channel (which gave me the best separation between the shady and directly sunlit regions) and corrected by selecting that white background.
That still left me with some color casts - particularly magenta around the white area that I didn’t believe to belong there - which I corrected with Color Zones.
I still think there’s some residual color cast, that could be further adjusted in Color Calibration or Color Balance RGB, but its a start.
Welcome to the forum, a good place to learn stuff…
Now, normal white balance isn’t really subjective, it’s what it takes to make R=G=B of a white/neutral patch in the light of the scene you care about. It would have been good to have an image of a whitebalance card in front of the flower, that’d let you determine the truth.
I just developed your image with all the camera defaults, except for the color primaries - I used my Nikon D7000 spectral profile, as most Nikons seem to have the same specs for their bayer mosaics. That gave a bit more saturated color:
Fascinating!! Honestly, i thought it was me being a numpty and not understanding anything at all about colour and white balance. I know the general theory, but this is really interesting.
The thing in the background is a knackered old wooden greenhouse, I think it’s the glass and chicken wire that can be seen.
I dug out the other photo I was talking about, which for me is just as difficult. Going to have a go at this one myself in about half an hour, see what i can do with all your advice.
(The attached file is licensed under the Creative Commons license CC0. You are free to do with it whatever you wish)
When selecting something to white balance off, in the absence of a grey card or anything that is obviously grey/black/white, how do you recognise something of colour that should be neutral?
On this second image, tried the method of selecting “as shot” in CC module, then switching to custom and tweaking hue and chroma. I can quickly arrive at something that looks more acceptable/normal.
I think I understand the hue setting, this sets the hue of the light source doesn’t it? But struggling with the chroma setting. As a test, I set the hue to 87.1 (which is a yellow) then I slid the chroma to minimum and maximum to get a feel for what’s happening. At minimum, the photo has a green tint. At maximum, the photo has a purple tint. In practical terms, what is happening as I tweak hue and chroma?
I have attached the XMP of my very quick and dirty edit, all comments about what I am doing wrong welcome.
Instead of “should be neutral” how about finding something of known color and globally adjusting the image to make that color correct?
For example, return to the scene and shoot the flower under the same lighting this time with a gray card nearby. Then white balance off the card and then color-pick the corrected flower color. Or better to shoot something man-made that will be in the scene, rather than flora. For example, a strategically placed flower pot.
This is similar in principle to shooting a color checker card and then white balancing off the mid-gray patch #18.
For such work, I find it better to deliberately blur an image so as to make the color of objects more homogenous.
