When you buy a brand new monitor for your MacBook, you are likely to run into one of three problems: the macOS interface is small, large, or cloudy. In this post, I’ll explain why this happens and how to choose a monitor to make macOS look as good as it does on an iMac.
Features of macOS: Retina and pixel density
Apple’s current lineup has four kinds of MacBooks and two kinds of iMacs. Everyone has a different screen size and resolution, but the macOS interface is the same in terms of clarity and proportions. Why?
To understand why this is happening, you need to understand the concepts of Retina and PPI. And since we’re talking about external monitors, let’s break these terms using the example of the iMac 4K.
The physical resolution of the 21-inch iMac 4K is 4096 × 2304 pixels, but the visible image is half the size – 2048 × 1152. This resolution is also called HiDPI. With this scaling, every visible pixel on your iMac is made up of four physical pixels. This is how Retina is made – high definition image.
To make macOS look equally good on devices with different diagonal and resolution, Apple tied the size of the macOS interface to the PPI (Pixels Per Inch) parameter – the number of pixels per inch that can be calculated from the diagonal and screen resolution.
The macOS interface looks good with PPI values of 110 for non-Retina and 220 for Retina. The MacBook 12 ″ and iMac 27 ″ have approximately the same pixel density: 226 and 216 PPI. So the font and button sizes seem familiar when we switch from MacBook to iMac.
Why is the macOS interface small
4K resolution starts at 3840×2160, also referred to as Ultra HD. In terms of the number of pixels, such a screen consists of four screens with a resolution of 1920 × 1080. And if you look at the range of any store, the vast majority of 4K monitors have a resolution of 3840 × 2160.
Alas, this 4K is not enough for macOS.
Each monitor always has its own “native” resolution. This is when the number of displayed pixels matches the number of physical pixels on the screen. For the picture to look sharp, macOS needs to run at 3840 x 2160 pixels on a 27-inch 4K monitor. But such a picture will look shallow compared to the iMac 27 ”.
This is because the PPI for 27 inches with a resolution of 3840 × 2160 is 163, which is much more than the standard 110. You will not be able to work comfortably at this resolution even with 100% vision. Everything will be too small.
Why is the interface large
The image will also be sharp if the visible image is scaled 200% so that each visible pixel consists of four physical ones. This is how Retina works: the native resolution of the 27-inch iMac is 5120 × 2880 pixels, but the visible resolution is 2560 × 1440.
For a 27-inch 4K monitor to work like Retina, its resolution must be downgraded to 1920 × 1080 HiDPI. In this case, one visible pixel will also consist of four physical ones, but with a PPI of 81. Because of this, the interface will become large, and the useful area of the monitor will be even less than in a 21-inch iMac 4K. Auch.
Why is the interface muddy
When the image on the monitor is too small, then the natural desire is to set the resolution lower in order to adjust the PPI value and increase the image.
For our 27 monitor, a visible resolution of 2560×1440 with a PPI of 109 would be ideal. But when the resolution is downgraded from 3840×2160 to 2560×1440, each visible pixel will take up 150% of the physical one. To get out of the situation, the video system will paint the neighboring pixels in the main shade. This is how we get dirty.
Some monitors scale the image better, some worse, but the fractional factor picture will not look as clear as the picture in the monitor’s native or HiDPI resolution.
Which monitor to choose
When choosing an external monitor for Mac, focus on pixel density. To do this, use the PPI calculator, into which you need to drive in the diagonal and resolution of the desired screen.
If the PPI is greater than 110 for non-Retina and 220 for Retina, the image will be too small. If less – more. To make things easier for you, I have compiled a PPI summary table for popular diagonals and resolutions.
Optimal in terms of price-quality ratio will be a monitor with a diagonal of 25-27 inches and a resolution of 2560 × 1440. Each manufacturer has such options, and the price starts at $ 350. The scale of the interface on such a monitor will look like Apple intended.
👉 View monitors on: Yandex.Market, Rozetka, Amazon