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I can normally reduce sky noise by importing two LR raw conversions into PS, one with significant noise reduction, and use layers to apply that to the sky only. However I have discovered a set of unprocessed photos from 2016 ( NEX6 ISO 100) where, for some reason, this is not working as effectively as I would like. I generally give the sky a bit of a lift in levels and can normally get away with it, but not this time. Applying additional noise control in PS helps a bit, but isn't the full answer. Curiously, if I apply a  linear curves adjustment, I also see  banding in the sky in one of the shots, not a real problem as I can mask that off, but it's another symptom of the malaise.

 

The shots were taken with wide angle lenses, 12 and 19mm, bright days, dark blue skies.

 

Any idea what is going wrong?

Edited by Bryan

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Have you considered alternative noise reduction software such as Neat Image?

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I find that most noise occurs when images are underexposed. I slightly overexpose and pull back the highlights in RAW. So I don't worry about it. What I do worry about is dust spots though. 

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2 hours ago, DDoug said:

Have you considered alternative noise reduction software such as Neat Image?

 

Not needed to in the past thanks, but maybe I need to take a look

 

49 minutes ago, vpics said:

I find that most noise occurs when images are underexposed. I slightly overexpose and pull back the highlights in RAW. So I don't worry about it. What I do worry about is dust spots though. 

 

Could be the problem. I've taken another look at the original histograms and they are biased to the left with no true whites. White buildings in the foreground have probably caused a degree of underexposure. I normally check the histogram after every shot, but these clearly got away!  Need to be more careful in future!

Edited by Bryan

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It's funny, but I recently decided that I've been too conservative regarding noise and high ISO. I plan to do more night shooting, without a tripod, and I'll be upping my max ISO from 800 to 1600 and 3200.  In film days, I shot a lot of Tri-X and developed it in Acufine. This produced a visible, even grain (think noise), which I thought was attractive (a later edit: 'attractive' is not the right word; 'exciting' may be better). These days I reduce the noise in LR and move on. 

 

Bryan, I hope you're not suffering from that condition known as: Yorkshire winter visual distortion with pronounced dark-days paranoia. 

 

Edo

Edited by Ed Rooney

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A dark blue sky might be Red 30, Green 130, Blue 240.

If you use a wide angle lens at F4, for instance, there will be vignetting causing underexposure in the corners resulting in Red 10, Green 110, Blue 220 in the corners. Red 10 is a noise area, so when your lens software tries to brighten the corners to Red 30, Green 130, Blue 240 the noise in the red channel will become obvious. The solution to the corners is to eliminate vignetting by stopping the lens down to your smallest usable F opening. On my full frame lenses that is F11.

Noise will also happen in the sky generally if the image is underexposed. It will also happen if you use a polarizer to intensify the blue of the sky resulting in Red 10, Green 90, Blue 220. Again Red 10 is a noise area.

The banding that you see is probably also mainly in the Red channel because at Noise 10 it only has a few luminance jumps between 10 and level 30. The luminance jumps will be obvious so you see the banding.

The solution might be to temporarily forget about the banding/noise and adjust the bottom layer (layer 1) to your taste. Then duplicate that adjusted layer (1). With duplicate layer (layer 2) on top, select the red channel only of the top layer, and run a median filter only on the red channel of the top layer. Watch the top red layer on screen at 100% until the noise disappears but banding intensifies. Now run a gausian noise filter on the red channel of the top layer (layer2) only adjusting the setting until you see the banding in the sky disappear. Usually level .75 or 1 for me.

Now create a black layer mask on the top layer (layer 2) so it does not show and you only see the bottom adjusted layer when both layers are showing. On the layer mask of the top layer (layer 2) with a large soft edge brush, paint white to allow the sky areas of (Layer 2) to show. If the noise in the new sky does not match the noise in the rest of the image then start all over again with a new (layer 2) and a different setting for gausian noise.

This can happen any time you try to adjust an image that has any one of the channels near a value of 10 or 245. As Vpics says overexpose, without raising the luminance of any one channel over 255, and then pull exposure back in software. Overexposure will raise the darkest channel up out of the noisy 10 value, and you can then adjust it back to 10, in software, without any 10 noise.

 

 

Edo:

There are strange things done in the midnight sun By the men who moil for gold;

The Arctic trails have their secret tales that would make your blood run cold;

The Northern Lights have seen queer sights, But the queerest they ever did see

Was that night on the marge of Lake Lebarge I cremated Sam McGee.

Now Sam McGee was from Tennessee, where the cotton blooms and blows.
Why he left his home in the South to roam 'round the Pole, God only knows.
He was always cold, but the land of gold seemed to hold him like a spell;
Though he'd often say in his homely way that "he'd sooner live in hell."

On a Christmas Day we were mushing our way over the Dawson trail.
Talk of your cold! through the parka's fold it stabbed like a driven nail.
If our eyes we'd close, then the lashes froze till sometimes we couldn't see;
It wasn't much fun, but the only one to whimper was Sam McGee.

And that very night, as we lay packed tight in our robes beneath the snow,
And the dogs were fed, and the stars o'erhead were dancing heel and toe,
He turned to me, and "Cap," says he, "I'll cash in this trip, I guess;
And if I do, I'm asking that you won't refuse my last request."

Well, he seemed so low that I couldn't say no; then he says with a sort of moan:
"It's the cursèd cold, and it's got right hold till I'm chilled clean through to the bone.
Yet 'tain't being dead—it's my awful dread of the icy grave that pains;
So I want you to swear that, foul or fair, you'll cremate my last remains."

A pal's last need is a thing to heed, so I swore I would not fail;
And we started on at the streak of dawn; but God! he looked ghastly pale.
He crouched on the sleigh, and he raved all day of his home in Tennessee;
And before nightfall a corpse was all that was left of Sam McGee.

There wasn't a breath in that land of death, and I hurried, horror-driven,
With a corpse half hid that I couldn't get rid, because of a promise given;
It was lashed to the sleigh, and it seemed to say: "You may tax your brawn and brains,
But you promised true, and it's up to you to cremate those last remains."

Now a promise made is a debt unpaid, and the trail has its own stern code.
In the days to come, though my lips were dumb, in my heart how I cursed that load.
In the long, long night, by the lone firelight, while the huskies, round in a ring,
Howled out their woes to the homeless snows— O God! how I loathed the thing.

And every day that quiet clay seemed to heavy and heavier grow;
And on I went, though the dogs were spent and the grub was getting low;
The trail was bad, and I felt half mad, but I swore I would not give in;
And I'd often sing to the hateful thing, and it hearkened with a grin.

Till I came to the marge of Lake Lebarge, and a derelict there lay;
It was jammed in the ice, but I saw in a trice it was called the "Alice May."
And I looked at it, and I thought a bit, and I looked at my frozen chum;
Then "Here," said I, with a sudden cry, "is my cre-ma-tor-eum."

Some planks I tore from the cabin floor, and I lit the boiler fire;
Some coal I found that was lying around, and I heaped the fuel higher;
The flames just soared, and the furnace roared—such a blaze you seldom see;
And I burrowed a hole in the glowing coal, and I stuffed in Sam McGee.

Then I made a hike, for I didn't like to hear him sizzle so;
And the heavens scowled, and the huskies howled, and the wind began to blow.
It was icy cold, but the hot sweat rolled down my cheeks, and I don't know why;
And the greasy smoke in an inky cloak went streaking down the sky.

I do not know how long in the snow I wrestled with grisly fear;
But the stars came out and they danced about ere again I ventured near;
I was sick with dread, but I bravely said: "I'll just take a peep inside.
I guess he's cooked, and it's time I looked"; ... then the door I opened wide.

And there sat Sam, looking cool and calm, in the heart of the furnace roar;
And he wore a smile you could see a mile, and he said: "Please close that door.
It's fine in here, but I greatly fear you'll let in the cold and storm—
Since I left Plumtree, down in Tennessee, it's the first time I've been warm."

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Bill, I hope you're having a relaxing holiday week up there in the Land of the Midnight Sun. 

 

I guess I need to say that if I have to deal with my photography in such a detailed scientific way as you've outlined above, I'll be boxing all my Sonys and bring them up to MPB for sale. 

 

Edo

Edited by Ed Rooney
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I select the sky with the selection tool in PS and apply noise reduction at 10%. Very simple, takes seconds.

I never get banding, but if I did, I’d use the tool in PS, can’t remember its name. I click a sample of the sky and sweep a fairly large brush over anything offending. That tool works and heals great (so is the name Healing tool?)  and seldom leaves a trail that looks different than surrounding colors.  It will smear, though, if you use it against a dark color. If that happens, I back up in History and using the color sampler tool to get a normal brush (tool) of that color, I carefully fix those areas with a brush using the color I sampled.

PS CC.

All of this takes only a minute or two.

Betty

Edited by Betty LaRue
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51 minutes ago, Bill Brooks said:

A dark blue sky might be Red 30, Green 130, Blue 240.

If you use a wide angle lens at F4, for instance, there will be vignetting causing underexposure in the corners resulting in Red 10, Green 110, Blue 220 in the corners. Red 10 is a noise area, so when your lens software tries to brighten the corners to Red 30, Green 130, Blue 240 the noise in the red channel will become obvious. The solution to the corners is to eliminate vignetting by stopping the lens down to your smallest usable F opening. On my full frame lenses that is F11.

Noise will also happen in the sky generally if the image is underexposed. It will also happen if you use a polarizer to intensify the blue of the sky resulting in Red 10, Green 90, Blue 220. Again Red 10 is a noise area.

The banding that you see is probably also mainly in the Red channel because at Noise 10 it only has a few luminance jumps between 10 and level 30. The luminance jumps will be obvious so you see the banding.

The solution might be to temporarily forget about the banding/noise and adjust the bottom layer (layer 1) to your taste. Then duplicate that adjusted layer (1). With duplicate layer (layer 2) on top, select the red channel only of the top layer, and run a median filter only on the red channel of the top layer. Watch the top red layer on screen at 100% until the noise disappears but banding intensifies. Now run a gausian noise filter on the red channel of the top layer (layer2) only adjusting the setting until you see the banding in the sky disappear. Usually level .75 or 1 for me.

Now create a black layer mask on the top layer (layer 2) so it does not show and you only see the bottom adjusted layer when both layers are showing. On the layer mask of the top layer (layer 2) with a large soft edge brush, paint white to allow the sky areas of (Layer 2) to show. If the noise in the new sky does not match the noise in the rest of the image then start all over again with a new (layer 2) and a different setting for gausian noise.

This can happen any time you try to adjust an image that has any one of the channels near a value of 10 or 245. As Vpics says overexpose, without raising the luminance of any one channel over 255, and then pull exposure back in software. Overexposure will raise the darkest channel up out of the noisy 10 value, and you can then adjust it back to 10, in software, without any 10 noise.

 

 

Edo:

There are strange things done in the midnight sun By the men who moil for gold;

The Arctic trails have their secret tales that would make your blood run cold;

The Northern Lights have seen queer sights, But the queerest they ever did see

Was that night on the marge of Lake Lebarge I cremated Sam McGee.

Now Sam McGee was from Tennessee, where the cotton blooms and blows.
Why he left his home in the South to roam 'round the Pole, God only knows.
He was always cold, but the land of gold seemed to hold him like a spell;
Though he'd often say in his homely way that "he'd sooner live in hell."

On a Christmas Day we were mushing our way over the Dawson trail.
Talk of your cold! through the parka's fold it stabbed like a driven nail.
If our eyes we'd close, then the lashes froze till sometimes we couldn't see;
It wasn't much fun, but the only one to whimper was Sam McGee.

And that very night, as we lay packed tight in our robes beneath the snow,
And the dogs were fed, and the stars o'erhead were dancing heel and toe,
He turned to me, and "Cap," says he, "I'll cash in this trip, I guess;
And if I do, I'm asking that you won't refuse my last request."

Well, he seemed so low that I couldn't say no; then he says with a sort of moan:
"It's the cursèd cold, and it's got right hold till I'm chilled clean through to the bone.
Yet 'tain't being dead—it's my awful dread of the icy grave that pains;
So I want you to swear that, foul or fair, you'll cremate my last remains."

A pal's last need is a thing to heed, so I swore I would not fail;
And we started on at the streak of dawn; but God! he looked ghastly pale.
He crouched on the sleigh, and he raved all day of his home in Tennessee;
And before nightfall a corpse was all that was left of Sam McGee.

There wasn't a breath in that land of death, and I hurried, horror-driven,
With a corpse half hid that I couldn't get rid, because of a promise given;
It was lashed to the sleigh, and it seemed to say: "You may tax your brawn and brains,
But you promised true, and it's up to you to cremate those last remains."

Now a promise made is a debt unpaid, and the trail has its own stern code.
In the days to come, though my lips were dumb, in my heart how I cursed that load.
In the long, long night, by the lone firelight, while the huskies, round in a ring,
Howled out their woes to the homeless snows— O God! how I loathed the thing.

And every day that quiet clay seemed to heavy and heavier grow;
And on I went, though the dogs were spent and the grub was getting low;
The trail was bad, and I felt half mad, but I swore I would not give in;
And I'd often sing to the hateful thing, and it hearkened with a grin.

Till I came to the marge of Lake Lebarge, and a derelict there lay;
It was jammed in the ice, but I saw in a trice it was called the "Alice May."
And I looked at it, and I thought a bit, and I looked at my frozen chum;
Then "Here," said I, with a sudden cry, "is my cre-ma-tor-eum."

Some planks I tore from the cabin floor, and I lit the boiler fire;
Some coal I found that was lying around, and I heaped the fuel higher;
The flames just soared, and the furnace roared—such a blaze you seldom see;
And I burrowed a hole in the glowing coal, and I stuffed in Sam McGee.

Then I made a hike, for I didn't like to hear him sizzle so;
And the heavens scowled, and the huskies howled, and the wind began to blow.
It was icy cold, but the hot sweat rolled down my cheeks, and I don't know why;
And the greasy smoke in an inky cloak went streaking down the sky.

I do not know how long in the snow I wrestled with grisly fear;
But the stars came out and they danced about ere again I ventured near;
I was sick with dread, but I bravely said: "I'll just take a peep inside.
I guess he's cooked, and it's time I looked"; ... then the door I opened wide.

And there sat Sam, looking cool and calm, in the heart of the furnace roar;
And he wore a smile you could see a mile, and he said: "Please close that door.
It's fine in here, but I greatly fear you'll let in the cold and storm—
Since I left Plumtree, down in Tennessee, it's the first time I've been warm."

It’s been years since I read that grisly poem. Maybe I was 10 and it was assigned by the teacher? Scared me.

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A really quick and simple way to decrease noise in skies without affecting the entire image is to use the grad filter in Lightroom or ACR with a large feather and just add local noise reduction. It won't work where there is a complex boundary with the sky but it will work well in many cases.

 

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Bill must be burning the midnight oil (or drinking it B)) over the holiday. Has anyone ever had a QC failure for sky noise? I haven't.

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Thanks for the responses folks.

 

Checked the red level before and after lens correction Bill, went from 65 to 83 in the corner. Using a crop sensor I  can't afford to stop down too far, I generally shoot at f8 if I have the choice.

 

Could carry out some tests, but......

 

Guess the problem is just one of underexposure generally. Other photos taken at the same time are OK.

 

EDo, we've had a few gloriously sunny days of late, 12.5 deg C on Christmas day in sunny Saltburn.  Getting colder and darker as I type.....

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49 minutes ago, MDM said:

A really quick and simple way to decrease noise in skies without affecting the entire image is to use the grad filter in Lightroom or ACR with a large feather and just add local noise reduction. It won't work where there is a complex boundary with the sky but it will work well in many cases.

 

Yep, my chosen method, too. (also works well for night skies and large non prominent background areas in high iso shots). Alternatively, if there are details in the that area that should not have noise reduction applied, then a brush with medium feather also works well.

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1 hour ago, Bryan said:

Thanks for the responses folks.

 

Checked the red level before and after lens correction Bill, went from 65 to 83 in the corner. Using a crop sensor I  can't afford to stop down too far, I generally shoot at f8 if I have the choice.

 

Could carry out some tests, but......

 

Guess the problem is just one of underexposure generally. Other photos taken at the same time are OK.

 

EDo, we've had a few gloriously sunny days of late, 12.5 deg C on Christmas day in sunny Saltburn.  Getting colder and darker as I type.....

 

I too prefer to not go beyond f/8, but f/11 is usually quite acceptable in good light, I find, even with my budget lenses. A little downsizing might be in order, though, which isn't a big deal IMO.

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On 12/26/2017 at 11:09, Ed Rooney said:

Bill, I hope you're having a relaxing holiday week up there in the Land of the Midnight Sun. 

 

I guess I need to say that if I have to deal with my photography in such a detailed scientific way as you've outlined above, I'll be boxing all my Sonys and bring them up to MPB for sale. 

 

Edo

 

I'm with you Edo!  Noise Ninja is another option.  For many years it was regarded as the best.  https://www.picturecode.com/nn_legacy/index.php 

 

Rick

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I used noise ninja until I got my first iMac and it didn’t work anymore. Selecting the sky and using noise reduction in PS works so well I don’t miss it. 

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In my experience, it is almost invariably far better to reduce noise working on the raw image than after conversion, which means that any Photoshop methods will not be as effective. Things have moved on a lot with noise reduction in Adobe software and the grad filter in LR/ACR mentioned above is very effective for local noise reduction, moreover as imageplotter says if using the brush tool for complex boundaries. The recent introduction of range masking for the grad filter in LR/ACR can make it a lot easier to selectively reduce noise in sky without affecting other areas even where there are complex boundaries. This is very quick in comparison to using a brush in LR/ACR or selecting a sky in Photoshop (which as stated above is generally a lot less effective in reducing noise than working on the raw image).

Edited by MDM
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All I can say is that using my PS method, which takes a matter of seconds, has never given me a failure for noise. So why would I not use it when it saves so much time? Absolutely no reason. I can’t argue with success. Maybe you can!

Betty

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Yeah, that PS quick selection tool works well and fast, Betty.  Thanks for reminding me of its existence.  

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I can argue with just about anybody as long as we are arguing about the same thing. Here I'm just talking generally, nothing to with Alamy QC, saleability of images or otherwise and I'm certainly not arguing with you. Your method is absolutely valid and, in the case of removing noise from sky, there may not be a lot of difference as you are not attempting to preserve detail in the sky as a rule. 

 

However, my key point here is that it is best in general to remove noise at the raw stage rather than after the conversion. Firstly, it is better in general to work on the raw image simply because it is a raw image and nothing has been locked in. Secondly, the noise reduction and sharpening algorithms in LR/ACR have been vastly improved over the years whereas Photoshop has not advanced much if at all in this respect as far as I know.

 

But there is a way to find out in fact. We don't have to talk in the abstract here. If you take an image shot at high ISO where you need to preserve detail as well as reduce noise (unlike sky where preserving detail is not normally important) and compare what you get doing this on the raw in ACR or LR (balancing sharpening with noise reduction) and do the same in Photoshop on the same image with no sharpening or NR applied before the conversion, I think you will find that you get a superior image using ACR/LR. I've tried this using various NR methods in PS (not clear which you are using in fact) and that is my consistent finding. It's not superior, it is far superior. 

 

However, I am always willing to learn though so if you would like to explaining your method I am very happy to try it.

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3 minutes ago, Ed Rooney said:

Yeah, that PS quick selection tool works well and fast, Betty.  Thanks for reminding me of its existence.  

 

If using PSCC, also try the focus area selection under the Select menu, as skies are usually out of focus. 

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1 hour ago, MDM said:

I can argue with just about anybody as long as we are arguing about the same thing. Here I'm just talking generally, nothing to with Alamy QC, saleability of images or otherwise and I'm certainly not arguing with you. Your method is absolutely valid and, in the case of removing noise from sky, there may not be a lot of difference as you are not attempting to preserve detail in the sky as a rule. 

 

However, my key point here is that it is best in general to remove noise at the raw stage rather than after the conversion. Firstly, it is better in general to work on the raw image simply because it is a raw image and nothing has been locked in. Secondly, the noise reduction and sharpening algorithms in LR/ACR have been vastly improved over the years whereas Photoshop has not advanced much if at all in this respect as far as I know.

 

But there is a way to find out in fact. We don't have to talk in the abstract here. If you take an image shot at high ISO where you need to preserve detail as well as reduce noise (unlike sky where preserving detail is not normally important) and compare what you get doing this on the raw in ACR or LR (balancing sharpening with noise reduction) and do the same in Photoshop on the same image with no sharpening or NR applied before the conversion, I think you will find that you get a superior image using ACR/LR. I've tried this using various NR methods in PS (not clear which you are using in fact) and that is my consistent finding. It's not superior, it is far superior. 

 

However, I am always willing to learn though so if you would like to explaining your method I am very happy to try it.

I do use the LR noise reduction always if the whole image needs it. It is superior.  But sometimes even if everything looks ok, my OCD about noise in the sky takes over. That's when I use the PS selection tool and noise reduction.  I never have really noisy skies because since going Fuji, I can see the exposure through the viewfinder before snapping. As a result, most skies are fine.  I tend to be overly concerned with sky noise because of my Nikon days.  So if I see a bit of grain there, I fix it.

Betty

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26 minutes ago, Betty LaRue said:

I do use the LR noise reduction always if the whole image needs it. It is superior.  But sometimes even if everything looks ok, my OCD about noise in the sky takes over. That's when I use the PS selection tool and noise reduction.  I never have really noisy skies because since going Fuji, I can see the exposure through the viewfinder before snapping. As a result, most skies are fine.  I tend to be overly concerned with sky noise because of my Nikon days.  So if I see a bit of grain there, I fix it.

Betty

OK. Clearer now after that explanation. But do check out the grad filter in LR/ACR with this new range masking feature if you get a minute or two. It's genuinely very useful, not just for removing noise but also for darkening blue skies and other things.

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I also use the color selection tool in PS. In many instances a couple of picks will allow you to select the sky and yet have minimal effect on the remainder of the image, it's more accurate than the LR tool and much less time consuming than carefully selecting areas using the quick selector and/or the pen. Doesn't work every time, but often a good solution. You can deselect sections that you don't want to include.  

 

Noise reduction using two raw conversions in LR and accurate blending using layers in PS is my normal route, although I sometimes additionally use the noise tool in PS. I've not done any tests, but it seems to work differently to the LR code, and can sometimes provide a fix. I have a theory, as yet unproved, and possibly totally wrong, that excessive noise reduction can lead to banding in the image. 

Edited by Bryan

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Yes I think if you need an accurate selection, then Photoshop is better than messing around with freehand brushes in LR. However, it is often possible to use a grad filter with a large feather as a very quick method of modifying sky in LR. I used to select skies in PS in the majority if my landscapes but do this a lot less now with the advancements in LR. As well, PSCC has the Camera Raw filter which gives all the functionality of the raw converter controls but I know your aversion to the subscription so you won't have seen that one. The workaround is simple though, save the image and work in it again in LR.

 

I don't know about your banding theory. I find I can get banding going from 16 to 8 bit and/or going too hard on skies with contrast modifying PS controls (Levels might be problematic). 

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