Mac External Widescreen Screen is Blurry? Turn on HiDPI to make it twice as clear!

In order to improve the efficiency of writing programs, I bought a relatively inexpensive 21:9 curved widescreen at work. After all, it’s a company device, so it doesn’t need to be too advanced, as long as it “works”. Recently, however, the screen has been acting up: the screen flickers, and sometimes it even says “no signal” and I can’t find the device. I thought the screen was broken, but I was able to replace the HDMI cable and the problem was solved.

It’s working, but it’s made me realize again that Macs with widescreen, especially 2K, have always had a problem with blurry resolution.

If you’re using a Mac with an external 2K widescreen, you’ve probably encountered this problem at some point:

• Although the default resolution is clear, the fonts and icons are so small that they are almost “unusable”;
• Although the size becomes more comfortable after manually adjusting the resolution, the image becomes blurry and looks like it is out of focus.

The reason for this is that the Mac’s Retina/HiDPI mode only supports certain resolutions natively. If the screen itself is stuck right in the middle of the resolution range, you’ll get blurry text. Then again, it only supports the Mac’s own monitors, or those that are partnered with it.

To solve this problem, I first used BetterDisplay (earlier called BetterDummy). The principle of BetterDisplay is very special — it utilizes the “Dummy screen” method to turn on HiDPI mode:

1. Create a fake virtual screen. 2;
2. Map the virtual screen to a physical screen. 3;
3. Set the HiDPI resolution on the virtual screen so that you can apply it to your physical screen.

In fact, I’ve been using it for almost three years and it’s not a problem. But the drawbacks are obvious:

• The interface is getting more and more complicated, there are a lot of functions but most of them are not useful.
• There are too many steps, you need to build a Dummy screen first and then manually adjust it, although you can set it up for the first time.
• Standby does not hibernate, I found that the screen will not turn off even when the computer is in standby mode, which is a bit of a waste of power;
• Some of the advanced features cost money, although the basic features can be used for free.

If you don’t mind the hassle and complexity of the interface, Better Display is a powerful tool for solving the blurriness of your Mac’s external screen.

Then I started to look for a simpler alternative and found an open source software: RDM.

RDM is not as complicated as Dummy screen and the interface is very simple. Although it has much fewer features than Better Display, it’s better for users like me who just want to “see without blurring and be able to adjust the font size”.

How I use it: with 3440x1440 screen

I have a curved 21:9 MSI screen with a native resolution of 3440x1440, and I’d like to see the screen enlarged a bit to make it more comfortable to look at, aiming for a zoom of about 75%.

The calculation is very simple:

Manually add a new resolution in RDM, then turn on HiDPI mode. After setting it Reboot, the new resolution option will appear in the menu. After setup, you will be asked to enter the password to change it twice, it is very important to Reboot for it to appear.

Comparison: Significant improvement in clarity

The following image compares the same resolution with and without HiDPI enabled.

It’s obvious — after turning on HiDPI, the fonts become clearer and sharper**, and the overall look is much more comfortable, without that fuzzy feeling. It’s much kinder to your eyes after working for a long time.

• Better Display: Powerful and flexible, but the operation is a bit cumbersome and may affect the standby status.
• RDM: Simple interface, intuitive operation, suitable for users who just want to quickly solve the problem of blurred resolution.

If you just want your screen to look clearer, RDM is a lightweight solution worth trying, but if you need more customization in your display settings, Better Display is more complete.

If you’re a Mac user with a 2K or 21:9 widescreen or higher resolution screen, and you’ve experienced blurry images, please leave a comment with your solution!

RDM: https://github.com/avibrazil/RDM

Better Display: https://github.com/waydabber/BetterDisplay

Originally published at https://vocus.cc