P: White balance dropper target location is offset on high-DPI Windows devices

[FeedbackCommunityMember]

There appears to be a bug affecting all recent versions of Lightroom on high-DPI Windows devices. It affects both CC and standalone versions, up to and including the current version (2015.6.1).

The issue is that when using the white balance dropper tool in the Develop module, the target location Lightroom uses does not correspond exactly to where the point of the dropper is located. Specifically, it seems to reference a position about 5 or 6 millimetres above the point of the tool.

The issue also affects the manual defringe dropper in the Lens Corrections panel. Other local develop tools seem not to be affected (brush, spot healing, HSL/Color/B&W picker, etc.).

To be clear: the issue affects Lightroom when the device is used in standard desktop mode with a regular mouse as the pointing device. It is not an issue with the touch screen, the pen or Lightroom's touch mode.

The problem is described in detail with screenshots here (in the original post and in my reply):
https://forums.adobe.com/message/8942657

It's also discussed briefly here:
https://www.reddit.com/r/Lightroom/comments/4wlf4i/lightroom_dropper_bug_on_surface_pro/

[Arnie47]

Still wrong:
I use a desktop PC together with a Samsung UHD Monitor U28E590 (28") and a dedicated 4k video adapter (Radeon RX470) and DO have the problem (see my post above with the red bass guitar two years ago).
It's also very annoying when drawing guiding lines in upright mode...

Of course everybody can always blame cheap or inadequate equipment.
But the issue does definitely also occur on desktop PCs with dedicated video adapters and big displays 28".

But even photographers forced to use HD mobile equipment should be supported.
It's really frustrating to pay a monthly fee for a program with massively troubling issues being reproducible by Adobe for 4 years and not being tackled.

[COBill]

Is your 28" monitor set to 175% scaling. If not, change it and see the problem disappear. 
 
"...photographers forced to use HD mobile equipment ..." HD works just fine, that is 1920x1080. It is 4K where the problem occurs. I've used Lightroom on HP and Lenovo FHD laptops and it worked fine, no display issues. 
  

[edrob]

I got my answer, thanks for the feedback. It is an Adobe issue that is unlikely to be fixed...soon.  And the work around is to drop the monitor dpi, or reduce the scaling (or get a bigger monitor.)

[Arnie47]

„... Is your 28" monitor set to 175% scaling. If not, change it and see the problem disappear.“

wow, that did the thing. I had set it to 185% scaling with offset documented in this issue.
Setting to 175% scaling just fixed the problem.
thank you, guys! That helps a lot.

[COBill]

Glad to be of assistance. 

[ChrigelKarrer]

I've used Lightroom on HP and Lenovo FHD laptops and it worked fine, no display issuesx


Again wrong,
i use Lenovo P70 laptop with 17 inch wide 4K 3840x2860 resulution and i am not able to get rid of this annoying bug. l Al other photo editing software i use and tested don't show this problem, so it's Lightroom related. I use now PhaseOne Capture One and it works just fine.

[croucrou.com]

I have a Lenovo P73 with 17inch 4K
Setting to 200% or 190% scaling
and i have the same issue.

If i set scaling to 175% it solve the problem, but all is too small on un 17inch

[COBill]

4K resolution is meaningless on a 17" display, the human eye cannot see the difference unless it is within a couple of inches. 4K monitors on laptops is just a marketing scam that also has the benefit of reduced battery life. Recommendation: sell the laptop and get one with a FHD display. 
  

[Fishweasel]

I am running a 36” 4K monitor at 125% scaling and the issue still occurs. It’s not just a “tiny monitor” problem.

[COBill]

Choose the default scaling and the problem goes away. This is a Windows issue, not Lightroom. 

• 32" = 150% 
• 27" = 175% 

[johnrellis]

"4K resolution is meaningless on a 17" display, the human eye cannot see the difference unless it is within a couple of inches."

Hmm, can you cite a reference for that? My rusty trigonometry indicates otherwise.

According to this Wikipedia article, "The maximum angular resolution of the human eye is 28 arc seconds. ... For a pixel pair (one white and one black pixel) this gives a pixel density of 128 pixels per degree (PPD)." My calculations show that, viewing a screen at a distance of 15", 128 pixels/degree translates to 488 pixels/inch.

The Lenovo P73 UDH screen is about 3840 pixels and 15.5" wide, for a resolution of 247 pixels/inch, about half than the maximum the human eye can distinguish. That doesn't seem meaningless to me...

[COBill]

I can't argue with the math but from an optical engineer I met several years ago, he gave the following limits to the resolution of the eye-brain system. To see a difference, one must be closer than:

• 1.5 times the diagonal for 720 
• 1 times the diagonal for FHD 
• 50% of the diagonal for 4K 

This would be 8.5" for your 17" 4K display. I've examine monitors in stores and my experience indicates that he is correct. I certainly support that with my 27" & 32" 4K monitors. 
 

[Fishweasel]

I don’t believe anyone is arguing it works in the native display. Many of us, however, need to increase the scaling due to eyesight challenges. This is not a just a Windows issue since it works with other programs. It’s Lightroom’s interaction with Windows - blame whoever you want for this issues but it was never a problem with Lightroom with 1080P resolution.

[ChrigelKarrer]

All other Windows Graphic programs don't show this misbehaviour on my 17'' Lenovo running at 3840x2160. I use my display for whatever application, from high-end games, architectural renderings, photo and video editing and i have no problem with any of the software i use.
In my house i have a Dell 27'' 4K Monitor and the same problem occurs, either in single monitor or twin monitor configuration, the damned eyedropper is offset.
This is definitively a problem of Lightroom for Windows and not of Windows as all other software works just fine without any offsets.
It is also unacceptable that Adobe ignore this problem, at least they could explain why they are not able to correct that.
On the end i cancelled all my Adobe subscriptions use now Capture One and it works just fine and no offset at any imaginable resolution.

[johnrellis]

Here's an article that starts with the assumption of "typical" visual acuity rather than "maximum" but comes to the same conclusion:

4K Monitors: Can you actually see the difference? 

"If you have average vision (which as we stated earlier is actually around 20/15 for a healthy adult), you would ideally want a 4K monitor at anything above a 14" screen size. This means that from a 14" laptop on up, the average healthy adult would ideally want to have a 4K screen. At the same time, unless you have 20/10 vision there should be no need for anything above a 4K screen on a laptop - so at least in terms of resolution a 4K screen is likely all laptops will ever need."

[croucrou.com]

the dropper works in photoshop and in caméra Raw, so adobe could do it

[Bob Somrak]

I agree this should be fixed.  Its been around for a LONG time.  You shouldn't have to mess with your scaling to make it work.

[Arnie47]

There are several issues about the mouse cursor Position being incorrectly handled (see also map module problems and problems     with the alignment of the horizon and alignment tools).
Some discussion threads recommend to change the LR fonts setting to a certain value others (like this one) to choose a certain windows monitor scaling option.

Somehow one has the impression that LR somehow guesses where the mouse pointer could be...
In some functionalities (spot removal, etc.) it works correctly independent of any font sizes and monitor scaling options, in other tools it always makes troubles finding the right position.

Adobe, please unify this mouse readings by implementing it clean together for all tools!
Having bugs like this for years doesn't meet professional standards!

[rayv56912865]

For the map issues I have been able to resolve by using the windows setting to control the Font Sizes and then setting LR Font Size setting to Auto (before it was set to a % value and I had problems). 
Also the <CNTL-left Click> or just the <right click> were fine workarounds for the map module.

I has not solved the White Balance Eye dropper issue (and the other Targeted Adjustment tools (eg HSL) are also off but by a very small amount which I can live with.)

[Rikk Flohr: Photography]

Version 9.3, an update to Lightroom Classic, went live on June 15, 2020 and contains a fix for this issue. Please install the update and respond back if it does not cure the issue for you. Thank you for your patience!

[croucrou.com]

yesss in my case the 9.3 update solve the problème

[Fishweasel]

Awesome!  This last update fixed mine!  Thank you!!!!

[COBill]

This problem will sometimes occur with a bad video card update for monitors over 4K resolution. It can also be caused by not using the Windows recommended Scale and Resolution. Not sure why 9.3 fixed this for you as you shouldn't have had the problem in the first place. 

[Fishweasel]

I'm not sure the intention of your comment that it shouldn't have been a problem in the first place but I would like to highlight a couple points:

1) the majority of comments listed above highlight the fact that it is an interaction between the scaling and resolution in 4k monitors.  I think many would acknowledge that it works in recommended windows scaling unless there are other issues.

2) many people, myself included, use a larger scale as the font is quite small in 4k resolution.  In my case, I scale to 125% due to eyesight challenges.

3) speaking for myself only, no other programs that I use have an issue with this scaling, and most Lightroom functions didn't have any issue other than the eyedropper.

This was clearly an issue for many of us, and speaking for myself, I'm grateful that Adobe was able to address this issue as it now works properly at 125% scaling on a 4k monitor.

[COBill]

I agree with you but we need to understand that this is a problem due to the way Windows manages scaling as well as the video card drivers. I think that it was great that the Lightroom team was able to come up with a fix but also that we should expect these kinds of problems until Microsoft redesigns its scaling implementation. In the interim, the only reliable solution is to use the defaults for scaling and resolution. Sad but true.