{"id":2976,"date":"2020-07-22T15:22:05","date_gmt":"2020-07-22T07:22:05","guid":{"rendered":"https:\/\/tzlee.com\/blog\/?p=2976"},"modified":"2020-12-01T21:29:01","modified_gmt":"2020-12-01T13:29:01","slug":"mac-and-dell-monitor-display-quality-issues-over-hdmi","status":"publish","type":"post","link":"https:\/\/tzlee.com\/blog\/2020\/07\/mac-and-dell-monitor-display-quality-issues-over-hdmi\/","title":{"rendered":"Mac and Dell monitor display quality issues over HDMI"},"content":{"rendered":"\n

Update: 2020\/12\/01 for macOS Big Sur, please follow instructions here<\/a>.<\/p>\n\n\n\n

If you have a MacBook, iMac, or Mac mini and use a HDMI cable to connect to a Dell monitor, you may notice that the image seemed over-processed as if it was over-sharpened<\/em> – I noticed this when I connected my MacBook Pro to my Dell U2913WM.<\/p>\n\n\n\n

I found a setting in the monitor to turn the sharpness down from the default 50 to 0. It improved the image quality some, but when I switched back to my Mac mini (which was connected via DisplayPort), the quality was still better.<\/p>\n\n\n\n

\"\"
Sharpness setting in the Dell monitor; setting to 0 made it look better, but still does not match a direct input via mDP<\/figcaption><\/figure><\/div>\n\n\n\n

It turns out that this is caused by the Mac sending video signals as YPbPr (component)<\/strong> instead of RGB. This can be seen in the Color Settings menu.<\/p>\n\n\n\n

\"\"
Color Settings showing Input Color Format as YPbPr<\/figcaption><\/figure><\/div>\n\n\n\n

Why does this happen? When a HDMI display is connected, the display’s capabilities are negotiated using what is known as an EDID. For some reason, Apple\/Mac decided to default to YPbPr, and there’s no way for us to select\/force RGB.<\/p>\n\n\n\n

I found this blog<\/a>, which also took a reference from another blog comment<\/a>. TL;DR, download a small Ruby script<\/a> and run it. The details are in those blogs, but I’m just writing it here for my own future reference.<\/p>\n\n\n\n

Steps:<\/p>\n\n\n\n