P: LR UI scaling/ rendering on MacOS when "scaling" in MacOS not 100% or 200%

[georgh3460921]

Hi,

Since Apple released Notebooks with "Retina" Displays that have a very high resolution and the size of UI Elements in Applications and the OS was not the typical size anymore I noticed a strange behavior in Lightroom. I use and 27" 4K Display and use typical 150 %or 125% Scaling in Mac OS so that I can read Icons an text. When I use 100% scaling everything is very small. Lightroom seems to act a little strange. When using OS scaling values between 100% and 200% Lightroom seems to render with 200% regardless of the actual value. You can see that when zooming into images in Lightroom. 200% and 100% zoom in images in Lightroom Classic are not real 100% and 200% anymore. Lightroom seems to expect that the actual resolution of the Display is always 200% of the Scaled version. 

I give an Example:

My 27" screen has 3840x2160 pixel. I use 150% Scaling in MacOS. So UI elements have the same size like an 27" screen with 2560x1440 pixels but it still is very sharp due to the good scaling implementation of MacOS. Lightroom seems to render all UI Elements with two times 2560x1440 pixels now. That is 5120x2880. An imported Image in Lightroom with that exact resolution and displayed with a 100% zoom fits the screen exactly. This should not be the case since my screen has only 3840x2160 pixels an with a 100% zoom it should be larger than my screen.

This leads to a performance drawback since Lightroom renders much more than required. Especially when you apply Scale values that are close to 100% but slightly more. 125% for example. On a 4K screen the Rendering is 3008x1692 pixel. Lightroom should still render in 4k but it things that my display has 6016x3384 Pixels. Its laggy and the zoom level are all over the place.

a

So please implement more than 100% and 200% scaling in MacOS. 125%, 150% and 175% at least. This will increase performance and the Zoom will work as expected. 100% Zoom will be 100%

[JohanElzenga]

The scaling of IU elements is actually correct. This is how MacOS can get such good scaling. Instead of having to upscale the IU elements from 2560x1440 pixels to the actual screen size of 3840x2160 pixels, it tells applications to display their IU elements at twice the size (5120x2880 pixels), so it can downscale this to 3840x2160 pixels.

The problem is that Lightroom should ignore this when displaying the image, and use the real native 3840x2160 pixels of the screen for that. Unfortunately, it doesn't but uses the same upscale/downscale for images. This is a long standing problem. Adobe should indeed fix this.

[georgh3460921]

Thanks a lot for your explaination Johan! That totaly makes sense for me. I checked PS2022 and it has the same behaviour. On my 34" 3440x1400 screen, 100% is 100%. But due to scaling on the 4K screen it is unusable. I assume that Adobe would fix PS first and since they did not even do that I am sure LR will not get a fix for an accurat Zoom in "scaled" OS environments. I will sell my 27" screen and get a screen where i can live with 100% or 200% scaling.

Is there a way to raise a request to Adobe? The old "feature request / bug report" page was disabled and forwarded me to this Support Community page. Not sure if any Adobe devs or support people red this and take note. If they even care

[JohanElzenga]

I have moved this to "Ideas", that is the feature request part of this forum.