P: Colored "pixel" artifacts/subdued blacks in shadow areas (older Macs) (also visible on CR)

[Andrej Michelcich]

I updated LrC to 12.4 yesyerday. Since then a number of pixels in multiple colors appear appear quite often on the image, mostly in the areas of blacks/darks and when using Tone Curve commands. It's similar to the red/blue pixels which denoted clipping in the areas of blacks/whites, but they appear in very many different other colors. Sometimes they disappear, or decrease, after actioning the commands again, sometimes they do not. Is anybody else facing the same problem which I encounter now for the vey first time after many years of use of LrC? Thank you in advance for your advise.

[John R Ellis]

"Furthermore, these are on devices still supported by Apple, running recent versions of macOS such as Big Sur or Ventura."

Even if a Mac is still "supported" by Apple, its graphic driver can and often does have bugs.

In the last couple of years, as Adobe has aggressively enhanced LR to use graphics processors (GPUs), by far the most common cause of reported display and AI masking glitches is buggy drivers, and usually updating the driver fixes the issue. There are hundreds of posts about this in this forum.  LR uses the graphics processor much differently than other categories of apps (e.g. games and video editing) and is constantly tripping over driver bugs.

On Windows, of course, that means getting the latest driver from the manufacturer's web site, but on Mac, you have to wait for the manufacturer to provide an updated driver to Apple and then for Apple to include it in the next release of Mac OS.

Unfortunately, the dozens of prior posts in this thread were lost due to a forum glitch, but Rikk Flohr accurately summarized the issue: most of the posts reported older Macs.  

Older Macs with Intel graphics chipsets no longer get updated drivers from Intel, since Intel has explicitly moved those chipsets to its "legacy support" model (i.e. no bug fixes).

Older Macs with the AMD Radeon R6 M390 are in a similar boat -- that graphics processor is eight years old and AMD announced it has stopped providing bug fixes.  A couple of the lost posts in this thread were from users with that GPU.

Mac users with an AMD Radeon Pro 5700 or RX 6600 reported bugs with AI People masking in the last five months. Some initial reports indicate that Mac OS 14 fixes the issue, strongly suggesting that Mac OS 14 includes updated drivers.  A Windows user with an RX 6600 reported very similar symptoms, and after updating his driver last month, the problem went away, again indicating the problem is likely with the Mac driver.

"The breakage happened between versions of Lightroom (12.3 -> 12.4), which points to a bug and missed QA by Adobe."

Adobe is constantly enhancing Camera Raw's and LR's use of the graphics processor. There are many reports here of a display or AI masking bug appearing as the result of a recent LR update.  While that could be cuased by a recently introduced LR bug, more likely it is the changed code in CR/LR tripping over a driver bug in a way that the old LR code didn't.

In general, CR and LR don't code to a particular graphics processor. They use the operating system's API for display operations and executing AI models, and the operating system relies on the manufacturers' drivers to translate those API calls into hardware-specific commands.  So if there's a glitch that only occurs with particular graphics processors, Occam's razor indicates that's probably a driver problem, not a LR bug. And the experience here that updating to the latest drivers usually fixes the problem supports that conclusion.

[Malcolm15C3]

There's always an apologist.  I've been developing software for 25 years and I always put the user first, even if that means working around spec-incompliant implementations.  Don't victim blame, Adobe has control over this.

[Sean McCormack]

You clearly don't read enough of @John R Ellis posts if you think he's an apologist. He's on here of his own free will helping people BECAUSE there are issues. He's been offered the chance to be a community expert but has turned it down so that his voice can always be seen as his own with no influence from Adobe. Speaking of developing, he also writes software and a lot of it is to fix issues or enhance where Adobe simply haven't done enough. 

[Malcolm15C3]

This is a straw man argument.

[DH-art]

Have recently been getting strange colour effcts on very dark tones. Only happens in Lightroom. Same file in Photoshop looks fine.

2013 Mac Pro running Monterey.

[John R Ellis]

@DH-art, see this previous reply:

https://community.adobe.com/t5/lightroom-classic-discussions/p-artifacts-resembling-clipping-odd-col...

[John R Ellis]

Adobe already provides a solution for buggy graphics drivers for older graphics processors no longer supported or poorly supported by manufacturers: Set Preferences > Performance > Use Graphics Processor to Off.

[sgillilan]

I clicked the 'HDR' button in the new version of LR (13) and it seems to fix these blowouts.  I don't have a HD Monitor, but for some reason it fixes the issue.  I have to tweak my image again for better results - but this has been a real pain.  My Macpro 2013 has enough graphics memory to handle the program, but Adobe suggests bad drivers.  I would suggest poorly written code or not addressing folks who cannot go out and buy a $5,000 Mac every few years to keep up with thier software.  

[BodaPhoto]

Over the last couple of months LR has been driving me nuts.
I cannot get rid of highlight/shadow clipping on my images.  I have ensured the clipping triangles on the histogram are not selected (both my clicking the triangles on the histo and using the J command)
I have also uninstalled and reinstalled LR.
It's still happening and its really stopping me from seeing the image properly whilst editing. 
The way I edit I dont want it 'fully' exposed and want to keep shadows etc

It's also appearing in Photomechanic
Is it time to go to Capture One?  Honestly had enough of this issue. 

Please help and suggest something I've not tried.  Example of image in PhotoMechanic.

[BodaPhoto]

Over the last couple of months LR has been driving me nuts.
I cannot get rid of highlight/shadow clipping on my images.  I have ensured the clipping triangles on the histogram are not selected (both my clicking the triangles on the histo and using the J command)
I have also uninstalled and reinstalled LR.
It's still happening and its really stopping me from seeing the image properly whilst editing. 
The way I edit I dont want it 'fully' exposed and want to keep shadows etc

It's also appearing in Photomechanic
Is it time to go to Capture One?  Honestly had enough of this issue. 

Please help and suggest something I've not tried.  Example of image in PhotoMechanic.

[GoldingD]

What version of Lr or LrC is this? From your image I suspect this is not LrC.

[Andrej Michelcich]

I read with much interest the whole thread of interventions and comments apparently originated by my post of June 14 and must realize with much disappointment that at today's date the problem has not been fixed yet; disabling GPU is NOT a solution. I also notice a that in these days Adobe has released Lightroon Classic 13.0; it may have addressed and fixed the issue but I will never know because, as far as I can see in my account, this new version is NOT COMPATBILE with my iMac, presumably because it is run under old — but up-to-date — Big Sur 11.7.10. So my only way-out would be to buy a new iMac and see. I still don't know if for this I have to thank Apple, Adobe or both, but this does not make me happy at all!

[John R Ellis]

"disabling GPU is NOT a solution."

Do you mean disabling does not cause the artifacts to disappear?

[Andrej Michelcich]

Most of the times artifacts disappear, but I believe that GPU is there to do its job and turning it off because by doing so you apparently fix another problem does not seem to me the correct approach. LR must work properly with GPU enabled, as the system itself claims immediately after turning it off.

[Malcolm15C3]

Sadly Lr Classic 13 still has this problem.

Sorry to hear you've been caught by Adobe cutting off "older" OSes.  It's actually very poor by Adobe not supporting anything older than a two year old version of macOS.  Even Apple, kings of end-of-lifing things, are still maintaining Big Sur.  Meanwhile, Adobe will be happy to take your monthly ransom for nothing in return while they roll in the cash, as they have since they ditched perpetual licenses in favour of renting their software.  On this occasion, this is nothing you can blame on Apple.

[John R Ellis]

"It's actually very poor by Adobe not supporting anything older than a two year old version of macOS."

LR runs well on most older Macs.

Would you prefer that Adobe hire specialists and fix the buggy graphics drivers for eight-year-old graphics processors that Intel, Nvidia, and AMD no longer support and then hope that Apple includes them in future releases of Mac OS?

[Malcolm15C3]

You're mixing topics: optional GPU support vs. Adobe completely dropping any OS older than two years old.

[John R Ellis]

You're right, I did get confused by the tangential change in topic from the main thrust of this thread.

[Andrej Michelcich]

Thank you for your sympathy. It isn't the first time, nor will be the last one, that we are victims of unfair commercial policies that nobody controls and that therefore firms manage in accordance with their own liking. As you pointed out correctly, if I want to continue to use LR I will have to continue to pay my monthly subscription for a product that for me is already and will be for ever out-of-date. Best regards.

[daveRedShed9UK]

This is shocking. Pretty sure that the  data adobe gathers includes machine data. I don't recall receiving an update that the service I am subscribing to will be impacted by their changes. 

There should be the option to run with older processors or opt out of subscription and just buy the last compatible version

Wonder what a contract lawyer would say about this?

[John R Ellis]

@daveRedShed9UK, which Mac and graphics processor do you have? Which version of LR and Mac OS? 

Many report that setting Preferences > Performance > Use Graphics Processor to Off avoids the problem. There are also some reports here that upgrading to Mac OS 14 (which gets updated graphics drivers) avoids the problem.

[Malcolm15C3]

To run macOS 14 Sonoma, you need at least one of these models or newer:

• 2019 iMac
• 2017 MacBook Pro
• 2018 MacBook Air
• N/A MacBook
• 2019 Mac Pro
• 2018 Mac Mini

Hardly old devices that fit your description of ones that will have out-of-date drivers that are no longer supported by the device manufacturers.  In this case there would be a fairly major problem that would be apparent to Apple.   The workaround is to either disable GPU support or roll back to Lr Classic 12.3.  Why don't you ever mention this last point?  Is it because it doesn't fit with your idea that it can't possible be Adobe's fault or something they should fix?

[daveRedShed9UK]

You miss the point. Adobe knows what we run. It gathers that data. There should have been some kind of service note to say it would stop working, including options to remediate as you mention. It would be different if the software was not a subscription but it is. As a subscriber I expect more, but hey. Don't let that stop you trolling

[John R Ellis]

"To run macOS 14 Sonoma, you need at least one of these models or newer: ...  Hardly old devices that fit your description of ones that will have out-of-date drivers that are no longer supported by the device manufacturers."

I have also described problems with graphics drivers in more recent versions of Mac OS, where the GPU is still supported by the manufacturers. For example, people with AMD Radeon Pro 5700 and the RX 6600 first reported problems with AI People masking April 2023. (Those processors are still supported by AMD.) A couple Windows users with the same GPUs reported the same symptoms, and they fixed the problem immediately by updating their drivers.   And now several of the Mac users report that, six months after the first report, updating to Mac OS 14 fixes the problem too, presumably because it includes the updated AMD drivers.

[daveRedShed9UK]

Thanks.  I'm on 12.5 on Monterey 12.2.1 Mid 2015 MacBook Pro.  I have few spare MBPs kicking about so I'll upgrade one to the latest everything and see what happens.  I'm in the middle of a huge edit at the moment so I don't want to try the regression option until I have finished!