So if I'm running my 2017 4k Retina 21" iMac at 1680x945, I'm not really getting any benefit from the 218 PPI the screen is capable of? My current eyeglasses work best at about 30" to 36" viewing distance. Or very close for the bifocals, which I don't like doing. I'm asking because I'm considering the new M4 Mini and a 24" monitor for it. 27" just seems enormous to me for simple usage such as internet browsing. But I'm not seeing 24" monitors that match the specs of the display on the new iMac. So I guess it boils down to do I need those iMac specs if I'm scaling the resolution for larger text anyway?
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Display resolution and PPI
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You don’t need 218 ppi, especially at your viewing distance. That said, a 24” 4k monitor would be beneficial to you. Running in a scaled 1680x945 will definitely look ok at your viewing distance.
Given the size of the pixels in a 24” 1920x1080 monitor (92 ppi), I suspect you would notice the difference and not be pleased trying to view at a lower resolution like 1680x945.
The 139 ppi of a 32” 4k monitor is the lowest pixel density I’ve ever used and been satisfied using at a lower resolution than its maximum.
Long story short, you don’t need 218 ppi, but you will appreciate 4k, even if you can’t push it to its limits.
Given the size of the pixels in a 24” 1920x1080 monitor (92 ppi), I suspect you would notice the difference and not be pleased trying to view at a lower resolution like 1680x945.
The 139 ppi of a 32” 4k monitor is the lowest pixel density I’ve ever used and been satisfied using at a lower resolution than its maximum.
Long story short, you don’t need 218 ppi, but you will appreciate 4k, even if you can’t push it to its limits.
1680x945 is probably a HiDPI (Retina) mode which means the Mac is rendering 3360x1890 pixels and scaling that up to 3840x2160 pixels.
https://tools.rodrigopolo.com/display_calc/ has a retina view distance calculator.
30" is a very long distance. A larger display might be better to get more display in your field of view. Since the display is usually far away, you maybe don't need 4K.
You probably prefer HiDPI. The LoDPI option will show text with the same size but with a quarter of the pixels.
https://tools.rodrigopolo.com/display_calc/ has a retina view distance calculator.
30" is a very long distance. A larger display might be better to get more display in your field of view. Since the display is usually far away, you maybe don't need 4K.
Code:
A 21" display with 1680x945 pixels 91.79ppi is retina at 37.46 inches. <- preferred (LoDPI)
A 21" display with 1920x1080 pixels 104.90ppi is retina at 32.77 inches.
A 21" display with 2560x1440 pixels 139.87ppi is retina at 24.58 inches.
A 21" display with 3360x1890 pixels 183.58ppi is retina at 18.73 inches. <- preferred (1680x945 HiDPI)
A 21" display with 3840x2160 pixels 209.80ppi is retina at 16.39 inches.
A 21" display with 5120x2880 pixels 279.73ppi is retina at 12.29 inches.
A 24" display with 1680x945 pixels 80.31ppi is retina at 42.81 inches.
A 24" display with 1920x1080 pixels 91.79ppi is retina at 37.46 inches. <- maybe preferred (LoDPI) since it matches 21" LoDPI option
A 24" display with 2560x1440 pixels 122.38ppi is retina at 28.09 inches.
A 24" display with 3360x1890 pixels 160.63ppi is retina at 21.40 inches.
A 24" display with 3840x2160 pixels 183.58ppi is retina at 18.73 inches. <- maybe preferred (1920x1080 HiDPI) - better performance since it matches resolution of 4K display.
A 24" display with 5120x2880 pixels 244.77ppi is retina at 14.05 inches.
A 27" display with 1680x945 pixels 71.39ppi is retina at 48.16 inches.
A 27" display with 1920x1080 pixels 81.59ppi is retina at 42.14 inches. <- choose between this
A 27" display with 2560x1440 pixels 108.79ppi is retina at 31.60 inches. <- or this for LoDPI option
A 27" display with 3360x1890 pixels 142.78ppi is retina at 24.08 inches.
A 27" display with 3840x2160 pixels 163.18ppi is retina at 21.07 inches. <- choose between this (1920x1080 HiDPI)
A 27" display with 5120x2880 pixels 217.57ppi is retina at 15.80 inches. <- or this for HiDPI option (2560x1440 HiDPI)You probably prefer HiDPI. The LoDPI option will show text with the same size but with a quarter of the pixels.
Ugh. This discussion is over my head and makes choosing a monitor for the new M4 Mini difficult, especially as my preferred 24" monitor size has a very limited availability in 4k.
If there are others checking this thread and, like me, have trouble with the topic, I found this post by 'theluggage' very helpful.
If there are others checking this thread and, like me, have trouble with the topic, I found this post by 'theluggage' very helpful.