It’s probably not the camera but the output medium (display). If you have a highly saturated red hue with a high dynamic range in luminosity it is nearly impossible to get a realistic representation on an 8 bit sRGB display.
Thanks again all. The WB was definitely off - it seems to have guessed 4800K. My guess is at the sunniest end of overcast - 6500K.
Some of the renderings above seem to be heading too much into yellow/orange for my taste which makes the flowers look like they are ‘going over’.
I hadn’t spotted the little bright patch - I guess this must be the sky reflecting from the edge of the waxy leaf because there is nothing bright behind the plant.
I take the point about the higher gamut monitors and limitations of sRGB but I like to share my better photos online so I guess I will need to live with ‘average’ display equipment and either accept dull red flowers or stick to photographing the less tricky ones. Sometimes I get things printed too… which is probably even worse for gamut.
there are two problems. the input device transform and the limited output gamut (srgb). if you look at this vkdt screengrab:
you’ll see the default processing using the D65 dng matrix and in the top right corner you’ll observe that much of the red is outside the smallest shaded triangle there (rec709/srgb), although within rec2020.
if i use an estimated ssf profile, i get this (at 6000k wb):
which still shows reds outside of gamut, but not nearly as pronounced as before.
take the images as illustrations with a good grain of salt: they are colour managed for my screen (not yours). so they will give you a rough idea, but the hard data is in the plot (top right corner).
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Take 1 without converting to sRGB standard (rec2020 linear → rec2020 standard[?]). The colours are darker and have been shifted further but reveal more detail in the flowers. Zoom for better viewing and contrast.
[?] sRGB curve?
Combining all that, we have
Take 3 – zoom to appreciate
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I had another go myself… looking at the real thing through the window. I couldn’t quite live with the 6500K white balance - it still makes the flower look too orange so played with it a bit more… 5500 seemed too blue so I spit the difference and 6000K seems (to my eyes) to be not terrible.
I think my main other changes are -0.45EV exposure, a color balance RGB preset based on ‘add basic colorfulness’ but with everything halved and then pushed global saturation up by 7.3%.
The brighter parts of the petals are trigger a clipping warning with ‘any RGB channel’. If I set the warning to ‘full gamut’ then the whole thing becomes a mess (which seems to be saturation) but I’ll live with it.
The real thing still looks a lot better 
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Hi Halina3000. I have encountered the same problem. Red flowers can be problematic. Many digital camera sensors have difficulty detecting subtleties at the red end of the spectrum. I’ve never been able to get truly satisfactory results when photographing red flowers. I end up having to make do with less than perfect. Some tweaking in Darktable or similar can sometimes help slightly, but unfortunately, there’s nothing much that can be done to obtain faithful realism when colour information is actually missing, due to the camera sensor’s limitations.
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I found that the red channel gets blown easily with red flowers, and that makes editing afterwards difficult.
In addition, there may be a bit of UV in many flower colours, which the camera can detect (as blue), but we don’t.
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The gamut compression slider in CC module can help and the colorfulness sliders also are nice to apply to help tweak those gamut/saturation issues
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Here’s my attempt. Tweaking color calibration to bring the blooms in line helped a lot
IMG_7089.CR2.xmp (11.2 KB)
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Edited in Gimp.
I lowered the exposure by about one stop and lifted the green channel using the red channel in brighten mode, then i blended the two layers in luminosity mode.
Hard to get a good contrast without blow out the reds and keep colors in gamut.
I see this topic has come back to life again
Give it another month or so and I should be able to compare with the real thing again.
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Not sure how many of these edit were done with the default DT web safe srgb profile… It seems geared to offer a perceptual rendering intent and although you can select rendering intents I am almost certain it doesn’t have the luts to render them… Switching to an icc from icc consortium you can change the rendering intent which in the case of flowers will also change the result…
Here are 4 exports of my edit… First one is perceptual with DT srgb profile and the second is relative…they seem the same and the next two are with the icc from the icc consortium…First one perceptual which is a good match for the 2 from DT and the last is rendered as relative and I actually like how it renders in this case…
IMG_7089.CR2.xmp (9.1 KB)
sRGB_v4_ICC_preference.icc (59.5 KB)
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Todd, they all look about the same to me. You embedded the relevant profile in each (proper practice), and most browsers are going to convert the image to sRGB (default) for rendition.
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The first 3 should be the same…you don’t see a difference on the last one???
How about in this screen shot…
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@priort, Thank you for the sRGB_v4_ICC_preference.icc from www.color.org. Different rendering intent do result in different rendering.
I do see a difference between the last two frames, also in original post, on my monitor.
They have another one on the same page called appearance… this one is supposed to help preserve color when there are color space conversions at least I think this is what it is for… its gives a slightly different result not sure I fully understand the difference between those two and this newer iccmax yet… Might have to read a bit to fully understand it…
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Bottom one is a teeny bit darker. Hues look the same though…