Detail slider revisited

[Tony Jay]

A little while ago there was a thread where questions were asked about the detail slider and how it worked.
I posted a couple of prominent vignettes on how this slider worked.

Nearly all the info posted was correct, however, one fact needs clarification.
I stated that if the detail slider was at 50 then the slider was doing nothing but if the the slider moved to the right from there an increasing deconvolution sharpening would be applied and if moved to the left from 50 an increasing halo suppression effect would be applied.

That statement is not quite correct.
In fact, at any slider setting apart from 0 and 100 there is a combination of halo suppression and deconvolution sharpening is applied.
The pattern works like this:
At 0 the amount of halo suppression is maximal and no deconvolution sharpening is applied.
At 100 the amount of deconvolution sharpening is maximal and no halo suppression is applied.
The amount of halo suppression gradually diminishes as the slider is moved to the right and the amount of deconvolution sharpening gradually increases.
Move the detail slider to the left and the opposite process occurs.

The original thread (or rather parts of it) were quoted on a forum in DPREview and it caught my eye.
None other than Jeff Schewe also noticed the thread and posted the correction.
(I do know Jeff from Luminous Landscape but have yet to meet him.)

In my defence I was paraphrasing Jeff's own explanation from his book "The Digital Negative" but clearly misinterpreted a key part of the understanding of how the detail slider works (as corrected above).

There was another small issue where I believe I was misunderstood, but again, for the purposes of clarification I will state again the point I wanted to make.
High levels of deconvolution sharpening (and hence low levels of halo suppression) will make noise more obvious. The amount of noise is not changed just accentuated.
Thus, if high levels of deconvolution sharpening are applied it may well require higher luminance noise reduction to counter the effect of the noise.

Because the whole rationale of this forum is to problem solve and to clear up confusion, not to mention my own personal values, I feel compelled to post this correction to those original posts.

Tony Jay

 

[Jimmsp]

Thanks, Tony, for this clarification.

 

[Victoria Bampton]

Thanks for sharing Tony.

 

[tspear]

Interesting, thanks for the clarification.

 

[Ian.B]

Cheers Tony, as always good info --- motivated me to look into sharpening a bit more as it does seem to be a bit of grey area where the 'exactly round about there' rule applies

maybe some need to start from the beginning although there is far more complex info out there
Learn How to Use the Sharpening Tools in Lightroom

One thing I don't use enough is the Alt / Option key :handsmack:

 

[Hoggy]

Yeah, that bit caught my eye too, but I didn't want to say anything.

But to add to this clarification, some more info that others might find useful regarding sharpening and noise reduction...

And, this bit is NOT verified! But I think internally LR applies the noise reduction first, and then the sharpening. I say this because I've noticed less white when using the option/alt-mask display when adjusting the sharpening masking - AFTER the noise reduction amount is increased. Which, when one thinks about it, makes sense - why sharpen noise?
___Due to that, I think this is one of the few areas where the order of adjusting can make a difference.. Not as in: one will get a different result if done in a different order. But as in: the amount of sharpening correction applied may need adjustment when realizing that.

This is just something I've noticed, and maybe someone with some more fortitude than I can check into and verify that.

 

[Tony Jay]

Hoggy, you are half right!

Lightroom does indeed have an internal order in the way that edits are applied - in this you are correct.
However, the order in which one edits will not make a difference if the same set of edits are applied since Lightroom sorts them out, internally, and applies them in its own order.
This is the essence of parametric editing!

The situation is completely different when using a pixel editor - in this case whenever an edit is applied the results are baked in immediately and so the order in which edits are applied is crucial. (This statement is not for your benefit but for a broader audience.)

The truth is that I often round-trip between "sharpening" and "noise reduction" especially when trying to fine-tune fine detail.
Each time when the dust settles I can see the optimised results of my fiddling with all the edits applied in perfect order by Lightroom.

I often apply sharpening and noise reduction presets on import based on lenses used and ISO. This is well before any tone or colour edits are applied. And as already stated, it is not unusual to need to fine tune both sharpening and noise reduction since accutance (the visual appearance of detail and sharpness) is a function of so many interrelated factors all of which are modified as one applies various edits.

The fantastic thing about Lightroom is that it analyses all the editing instructions and in summary terms applies the net edits in optimal order to produce the best result. This occurs on the fly when Lightroom is updating the previews one views in the Develop module and also when Lightroom is instructed to produce a derivative file based on those edits.

Tony Jay

 

[Hoggy]

Hoggy, you are half right!

Lightroom does indeed have an internal order in the way that edits are applied - in this you are correct.
However, the order in which one edits will not make a difference if the same set of edits are applied since Lightroom sorts them out, internally, and applies them in its own order.
This is the essence of parametric editing!

The situation is completely different when using a pixel editor - in this case whenever an edit is applied the results are baked in immediately and so the order in which edits are applied is crucial. (This statement is not for your benefit but for a broader audience.)

The truth is that I often round-trip between "sharpening" and "noise reduction" especially when trying to fine-tune fine detail.
Each time when the dust settles I can see the optimised results of my fiddling with all the edits applied in perfect order by Lightroom.

I often apply sharpening and noise reduction presets on import based on lenses used and ISO. This is well before any tone or colour edits are applied. And as already stated, it is not unusual to need to fine tune both sharpening and noise reduction since accutance (the visual appearance of detail and sharpness) is a function of so many interrelated factors all of which are modified as one applies various edits.

The fantastic thing about Lightroom is that it analyses all the editing instructions and in summary terms applies the net edits in optimal order to produce the best result. This occurs on the fly when Lightroom is updating the previews one views in the Develop module and also when Lightroom is instructed to produce a derivative file based on those edits.

Tony Jay

Yep, that's what I was trying to say by the part (emphasis added):
"
Due to that, I think this is one of the few areas where the order of adjusting can make a difference.. Not as in: one will get a different result if done in a different order. But as in: the amount of sharpening correction applied may need adjustment when realizing that.
"
Although, it's likely that I may not be saying it as correctly as I could.
I'm trying to say that one might want to do the noise reduction first.. Therefore lower sharpening settings may be required. (EDIT: or higher sharpening.. Dunno.. I'm having trouble finding the right words of what I'm trying to get across, right now.. late+cognitive disability makes for a really messed up thought process at times. )
Of course it's still highly likely that one will need to bounce back and forth between the two, if noise reduction is called for.. Since the two are quite interconnected.

 

[Tony Jay]

It is also true that Adobe broadly recommends a top-down approach to editing starting with the basic panel and then moving down.
In this instance sharpening comes before noise reduction.

In broad brush strokes I think they are correct but it does not necessarily always reflect how I work.
But, IMHO, it is sharpening that is the primary edit, and noise reduction the secondary edit.
In other words accutance is my primary goal and noise reduction is the secondary goal.
I am pretty sure that applying noise reduction first will not reduce the amount and nature of sharpening edits I would want to apply to an image because I sharpen for accutance, not primarily to limit the visibility of noise.
I admit that the masking slider is extraordinarily helpful in being able put my focus first on edge sharpening (accutance) and then look to minimise noise on surfaces and skies etc that firstly should not be sharpened that can usually be controlled with fairly minimal noise reduction.

But, absolutely, as I have already mentioned, at least some round-tripping between sharpening and noise reduction, is a given in order to fine tune detail on an important image.

Tony Jay