Lightroom and pixel mapping 1:1 using scaled 4k resolution (osx)

[itshardtochoosealcd]

Hi there,

I am thinking of being a nec 4k monitor (ea275uhd). I will connect it to my retina macbook pro. I was wondering if I scale this thing to 1440p, I have heard reports that Lightroom will also be scaling the pictures in the software so the pixels displayed by the photo will be bigger than 1:1. Is this something caused by Apple scaling technology or by Adobe? Is there a way to fix this? I know I could buy a 5k display, but they are pretty expensive.

I was wondering if It wouldn't be better to just buy a 1440p screen like the nec Pa272w. I don't really need AdobeRBG though. Also, if using native 4k resolution on a 27 inch display doable for when I just need to do photo editing?

Thank you very much for your help!

 

[zone74]

OS X will only ever render the UI at 1x or 2x scale. It does not support rendering the UI at non-integer scales like Windows.
So you cannot get 1:1 pixel mapping at anything other than your display's native resolution, at 1x or 2x scale.
The way that OS X handles virtual resolutions is that they are rendered natively at 2x, and that result is then scaled - as an image - to your display's native resolution.
Though I know that a lot of Mac users are happy with display scaling, the result is unacceptably blurry in my opinion - at least on anything ≤230 PPI. (I own a 227 PPI Retina MacBook Pro)

So "1440p" on a UHD screen would be rendering 5120x2880 (1440p @2x) and the output would then be scaled down to 3840x2160.
For photo editing, a UHD screen would be better than a 1440p one due to the higher resolution - more resolution is always better for photo editing - but only if you use it at 1x or 2x on OS X.