Art zoom in 1:1 is bigger on screen then 100% in Lightroom

Hi, i am on mac mini m1 with benq sw270c monitor at resolution of 2560x1440.

If I open an image in Lightroom on that monitor and zoom to 100% it looks ok.
Photoshop shows it at the same size.
BUT if I open the same image in art and zoom to 1:1 the image looks twice as big on the screen as the ones in Lr and Ps.
To have them similar, i have to zoom to 50% in Art.

What could cause this ?

Hi, it’s probably a problem with high dpi / retina displays. What happens if you change the value of “pseudo hidpi mode” in preferences?

You are right !

The resolution setting on my mac for the sw270c was 2560x1440 ( this is the hidpi )
There is also a 2560x1440 low resolution setting ( this is the non-hidpi )

I have set the resolution on my mac to 2560x1440 non-hidpi and now the scaling looks fine.

Thanks

I seem to have a similar problem, on an iMac Retina 27" which is set to its standard resolution of 2560x1440 - preview in the Editor view is blurry, and if I zoom in to 100% it’s also blurry and double the size of a true 1:1 display (which would use the iMac’s native 5120 x 2880 resolution) .

PseudoHiDPISupport in the options file is set to false, manually changing to true has no effect - I can see in the source code, that the option is ignored and the corresponding value permanently set to false for Apple.

Probably I misunderstand the purpose of this flag? What am I doing wrong?

Do you use UI scaling at the MacOS level? That might scale the image in ART (just guessing; I think I’ve had similar experience with darktable, I cannot recall if that was under Windows or Linux).

Probably that’s the case - 2560x1440 is marked as „standard“ by the OS and what is selected by default, although they real resolution of the display is 5120x2880.

I assume that for UI elements the lower resolution is reported to applications, and the OS does the scaling to achieve „Retina“ sharpness.
For pixmaps, the real resolution is obviously used in applications, like in darktable - but apparently not in ART.