I recently upgraded to 27" monitors. Every other game works perfectly fine and I can adjust my resolution without any issues.
In DayZ I can only adjust to 1200/800 and every thing is blurry. It will not give me any other higher resolution settings. I can play everything else on 1980x1200.
You're probably trying to change your rendering resolution.
In Configure, click 'Video' then 'User Interface' and you should have a drop down menu for resolution, set that to 1980x1080.
Now go back to Video and change your rendering resolution to match that, it should say 100%.
Hello Sidescan,
as Dennooo said, you are probably attempting to change Rendering Resolution rather than the actual Resolution, which can be found in Configure -> Video -> User Interface -> Resolution.
Please let me know if this helped.
Thank you.