Not sure that what I said was incorrect, sorry.
It occurred to me that Iāve been using a preview build that has capture sharpening, and I just havenāt been using it.
First impressions areā¦ WOW! I really need to think more about sharpening in my photos but this seems like a huge step up for me.
I have a question about how it works, just so I understand how best to use it. I have a lot of photos where there is a relatively smooth blurry background and normally I would use diffuse or sharpen and contrast equalizer with a drawn mask around the subject, just so the background noise doesnāt get affected. Since the demosaic module canāt have a mask the only way to control whatās being sharpened is the contrast sensitivity, but I find that adjusting it to so itās not sharpening the background pretty much removes the sharpening from many points of interest (such as the eye in this case).
HOWEVERā¦
I donāt really notice much of a difference in the background anyways if I donāt adjust the contrast sensitivity. In the screenshots below, fully zoomed in:
- No sharpening
- After applying capture sharpening (no changes the auto calculated values)
- The mask
I did notice slightly more difference on an image with a lighter background, but the type of difference that I only saw fully zoomed in and even then itās questionable how much of a difference Iām actually seeing.
So for my own sanity, is capture sharpening pretty good about not increasing noise even if the mask is covering those areas? Worst case scenario I can invert my subject masks and apply some negative clarity or something if needed.
I suspect like DorS you may need to view things with the HQpreview enabled to get an accurate assessment of the adjustment.
EDIT
And there were some good notes linked above by @kofa
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Excellent thank you. I forgot about the high quality processing. I just checked again with that enabled and saw similar results.
From the PR notes:
contrast threshold
As sensor noise will be amplified by CS we take some care about this by a per pixel variance analysis and use a logistic function with this threshold to avoid CS in noisy areas. The default is good for low iso images.
To me this implies that there is some additional analysis going on in addition to the mask, but maybe Iām misinterpreting that.
I havenāt tested yet I just suggested it as even without considering this there can be quite a difference esp in the perception of sharpness when this is on vs off and one module in particular that can look substantially different between previews is D or S if usedā¦I was assuming likely visual assessment of CS would or may also be impactedā¦I recently exported fairly low quality playraw attempt of the ravenā¦there you can see looking at the tree bark how the grain/sharpness can appear quite different so its something to be considered for all discussions around sharpness evaluation when talking about modules and workflows in DTā¦
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This is a followup from my earlier question that Iāve posted on the dt 5.4 announcement:
First time for me trying the new capture sharpen option in demosaic, Iāve read the github discussion mentioned in this thread but I wonder about the ācontrast sensitivityā value.
Consider this first exampe (iso 100, good lens/good camera/good light ā eos r with 35mm f1/.8):
I have increased the contrast sens from the default which was this, (the thinking was, Iām applying this to the flat parts of this image so I should dial it back i.e. increase it from 0.27):
Is this sort of reasoning correct?
Now an example of an ISO6400 image (same camera, eos r with rf70-200 f4): do I accept the increase sharpening of the noise?
ā¦or should I again, ādial it backā i.e. increase the sensitivity to 0.48 and only focus on the subject in foreground?
Yes, thatās the idea, although itās completely up to you to decide what gives you the look you want.
As a rule of thumb, you are looking to sharpen details on your subject and NOT sharpen noise (or blurred areas), so your first and last images above fit with that philosophy. Usually, as soon as the yellow flecks creep into an area like a clear blue sky, thatās a sign that you are oversharpening and need to back off.
But there are certainly times when you can add more sharpness and the noise still wonāt look bad. It can even add pleasant grain in some shots.
Note that on images shot with higher ISO, you may never be able to fully āmask outā areas with less detail (because the noise adds details everywhere), so thereās a bit of a compromise needed. I just keep turning off the mask and using my eyes to judge what I can get away with. For tricky images, I would tend to use higher contrast sensitivity with Capture Sharpening, and then use another module like Contrast Equalizer to do final sharpening (because you can use masks to ignore areas with less detail).
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This!!
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Just 2 comments
- Itās not really necessary to finetune the contrast sensitivity control, the defaults are set from iso and sensor precision and are mostly fine. A rule of thumb if you want to check, the mask should be mostly black in noisy parts.
- remember, you can define an auto applied preset with radius and contrast sensitivity both set to zero and dt will calculate both accordingly when importing. I am using this personally for all images with iso < 3200 since a while.
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If you have two different sensor types, which use different demosaicing methods, do you need different auto applied presets for each type?
And when you say āimportingā, does this also apply to clearing the imageās history and starting from scratch?
Nope, if will fallback to the default of the other sensor (RCD, Markje1)
Sorry, yes of course. fresh history while importing for the first time or clear history.
BTW - thatās now in the current manual 
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