Edge threshold is a good one to use when noise or grain appears but I think pixel peeping can often result in over smoothing…if you take all the grain out of the image it will for sure be less sharp esp when zoomed out so its always a trade off here and the destination or intent of your image may dictate the balance you choose…
The slider that you want to adjust is the details threshold slider in the masking option. I use this often. A positive value on the slider limits sharpening to the details (see image below) so the noise is not sharpened in the image. A negative value protects details from the softening effects of denoising. This is critical to my work flow with high ISO images.
I learnt about this on the forum. Possibly from @priort. I shoot a lot of high ISO images and the feature is brilliant. Also in the denoise (profiled) there is a slider to preserve shadows. It reduces the shadow noise in noisy images when it is set to a lower value than default. It is important as well.
Here’s my two-penny bit of D&S and DeNoise modules. I learnt about its usage from two videos, One by BorisH, and the other by BruceW. Take some time out and watch how they use them. Most queries are likey to get solved
@nwinspeare Actually has 2 that are very good and both easy to understand or mostly and well presented…They should be on any video list for that module
What you were seeing was noise, but noise enhanced by the module:
you are using DorS to sharpen, i.e. to enhance any edges. Noise creates lots of edges, and can cause very steep gradients. Now, you can compare diffusion with balls rolling down a slope: the steeper the slope, the faster the balls will move. So the further they will move in a given time.
In terms of DorS, that means that on sharpening, a steep edge will get enhanced more.
What doesn’t help is that the sharpen presets use very small radii, so the influence of the fine-detail layers is very strong. Those are the layers with the noise…
Personally, I find the “lens deblur” presets more pleasant in their effect. Or, if I need much sharpening, the contrast equaliser “sharpen” preset works well.
But with any preset, at their default settings I do not get a “tremendous amount of noise” visible, unless I increase the number of iterations (at least double the number). Then again, I almost automatically use profiled denoise…
So I presume you are talking about the details threshold slider adjustment to sharpening and denoising. I have never noticed harsh transitions, but will look more carefully in the future. How big a problem is this and how often do you observe this?
I often use the lens deblur presets as part of my sharpening strategy in combination with an instance of antialaising sharpening preset.
The denoise presets of fine, medium or course in the DorS module are also very good, but I use snapshots to compare the effect between the various presets. The DorS module is another great module in DT.
That is what I was getting at or use some blur, feather contrast if necessary … There is a natural gradient to some edges and pushing the details to the extreme and then sharpening them can create artifact in some random area… but its a nice additional tool to refine the area of masking
I will keep an eye on that problem. I use a 43 inch monitor so I would have expected to see any problems. Also maybe I am not pushing too hard on the effects anyway. The ability to feather masks is a godsend for getting smooth transitions.
I use the “sharpness-strong” setting on a regular basis along with ISO 800 on a Fuji/Sony sensor and at 100% see little or no signs of noise. Only at 200% does some slight noise become apparent.
All of the potential settings I do find confusing but overall the results are significantly better than any other procedure that I am aware of.
It’s not adding noise, its amplifying the noise that’s already there.
Sharpening and local contrast are. Oth techniques that have the purpose of making differences between areas more noticable. Be it very small areas , somewhat bigger or very big areas.
Noise is ‘difference between neighboring pixels’ (very crude statement. I know, but roll with it ). maybe the noise is there , but the differences are so small you don’t notice it. ‘making the differences more noticeable’ makes that you suddenly notice the noise more.
The way to prevent this is to somehow come up with a method to skip the 'make more noticable ’ on parte you dont want to notice more. Deciding what’s what is always where the challenge lies in this problem:).
Working with something of a ‘threshold’ is a simple method. “If the difference is this small, keep it this way. Otherwise enhance it”. But this lessens the sharpening effect for areas where the difference are small. And if you lower the threshold , more will sharpen but also more noise will be sharpened.
Playing with a (subtle!) denoiser before the sharpener can also sometimes give more pleasing results.
All the ‘ai’ denoisers and sharpeners are a different way , but it comes down to the same problem: it’s hard to decide for an algorithm what is a subtle difference you want enhanced, and what is something you want to be left alone (or even removed).
Not sure sliders behave differently for each DT user, I highly doubt it however copying the slider values as it is for other pics doesn’t work so well and understandably so. E.g this video from Boris, when i tried using similar slider values I dint get pleasant result what he got. I always have to tweak it, sometimes just a bit and at times quite a bit to get the desired results.
Surprisingly, for me “lense deblur: medium” OOB preset works pretty well.
Unfortunately, local contrast module is bit scary to use at least for me! it thickens the sharp edges way too much. Probably I need to play around with the adjustments but I found D&S lens deblur:mediuam preset working for me without needing any further adjustments so never got back to local contrast anymore.
In V4.8 there should be a new preset called local contrast fine and this has a significant sharpening effect and ability to bring out rich detail. But beware of over sharpening images as many good images are wrecked by overambitious sharpening.
