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User profile for user: thebanduu
thebanduu Author
User level: Level 1
8 points

MacOS showing external monitor's size (inch) wrong.

Computer:

MacBook Pro (16-inch, 2019), 2.6 GHz 6-Core Intel Core i7, 16GB of RAM, GPU-AMD Radeon Pro 5300M, Intel UHD Graphics 630.

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External Monitor:

LG 27UP850-w, 27 inch, 4K Monitor

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Problem:

When I go to the "Display" in "About This Mac", MacOS is showing my external monitor as a 31,5 inch monitor (screenshot attached). Because of this issue the only way I can see texts and small details clear is to set the resolution to 1920x1080, other higher resolutions in "Scaled" settings and the "Default for Display" settings makes text and small details blurry/fuzzy.

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Question:

Is this a MacOS issue or could it be the monitor manufacturer's issue?

Does anyone having this issue?

What can I do to use my external monitor the way it should be?





Screenshot of MacOS showing incorrect size:


MacBook Pro 16″, macOS 11.5

Posted on Aug 16, 2021 7:24 AM

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User profile for user: ivan54
ivan54
User level: Level 4
2,858 points

Posted on Aug 16, 2021 8:44 AM

Howdy,


I do not have the LG 27UP850-w, 27 inch, 4K Monitor, but there are a couple things I would try if I did.


  1. See if changing the Monitor's Aspect Ratio setting to Original or Just Scan changes things. Normally the Mac senses the display capabilities and offers the correct options. If those are not reported correctly by the display, odd things can happen.


( Manual available at https://www.lg.com/us/support/manuals-documents?csSalesCode=27UP850-W.AUS )


2. Download the display drivers and software to see if they help.

https://www.lg.com/us/support/software-firmware-drivers?csSalesCode=27UP850-W.AUS


Also there's Monitor - Connecting to a Mac


ivan

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User profile for user: ivan54
ivan54
User level: Level 4
2,858 points

Aug 16, 2021 8:44 AM in response to thebanduu

Howdy,


I do not have the LG 27UP850-w, 27 inch, 4K Monitor, but there are a couple things I would try if I did.


  1. See if changing the Monitor's Aspect Ratio setting to Original or Just Scan changes things. Normally the Mac senses the display capabilities and offers the correct options. If those are not reported correctly by the display, odd things can happen.


( Manual available at https://www.lg.com/us/support/manuals-documents?csSalesCode=27UP850-W.AUS )


2. Download the display drivers and software to see if they help.

https://www.lg.com/us/support/software-firmware-drivers?csSalesCode=27UP850-W.AUS


Also there's Monitor - Connecting to a Mac


ivan

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User profile for user: thebanduu
thebanduu Author
User level: Level 1
8 points

Aug 17, 2021 8:01 PM in response to ivan54

Yeah, I contacted with LG care and not much of a luck.

Found a guy on youtube who unboxed 27UP850-w and connected it to his MBA M1. Asked him if he is having this issue and he said YES. Here is his video: https://www.youtube.com/watch?v=4TWAeMLrWEs

I guess it is MacOS issue cause I found several posts about having issues with external monitors here in the forum. :(


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MacOS showing external monitor's size (inch) wrong.

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