12 Oct 2020

Finding the right MacBook Pro external monitor for design

I recently joined a startup and, as the first designer, was responsible for finding the right monitor for a design team. What I thought would be a quick price comparison ended up being a multi-week dive into the technicalities of monitor resolution and sizing. I scoured dozens of articles and YouTube videos and began compiling my research.

I hope this article saves you time and allows you to be more decisive in picking the right external monitor for your MacBook Pro.

Ever since Apple stopped producing their Thunderbolt displays (and started charging several thousand dollars for for the Pro Display XDR), Apple users have been scrambling to the find the best affordable monitor as an external display to a MacBook Pro.

Here was my criteria when reviewing monitors, in order:

  • Color accuracy
  • Resolution/PPI
  • Price
  • Connection types

TL;DR the monitor market hasn’t quite caught up to retina screens. The most popular monitors right now (2020) are 27” 4K screen that have about 75% the pixel-density of a retina screen and thus don’t render retina UI very well.

Your options are:

  • Get a smaller (~21”) 4K screen
  • Deal with the rendering issues of a 27” 4K screen until 5k screens become cheaper (what I’m doing)
  • Spend the money for a 5k screen

I ended up purchasing the Dell Ultrasharp U2720 Inch 4K (for its recommended brightness and color accuracy, despite the blurry rendering of retina UI) while I wait for 5K monitors to become more affordable.

🌈 Color Accuracy

Here’s the thing: the screens on Apple devices are amazing. It’s going to be hard to find color or resolution that can rival an Apple screen, but that doesn’t mean you need to break the bank to do good design work.

If you do any kind of digital design (UI design, digital advertising, etc) then there are a few elements to look for in a monitor:

  1. As close to 100% sRGB (standard Red Green Blue) color gamut as possible. This refers to the monitor’s ability to display all the colors possible in the sRGB range. The farther away from 100% you get, the less color accurate the monitor will be.
  2. Factory color calibration. Some monitors will be color calibrated before they leave the manufacturer. If yours isn’t, you may find yourself buying one of these to calibrate your monitor yourself (I’ve used one and didn’t notice a big difference, to be honest).
  3. IPS (In-Plane Switching) monitors. These types of monitors feature “faster response times, wider viewing angles, better color/contrast… [and] outstanding color accuracy and screen consistency” (Viewsonic).

(If you do print work (CMYK) then I apologize, I have no advice for you.)

My advice: Pick a monitor that has near 100% sRGB coverage. If you can’t test it yourself, watch YouTube videos to read about light leaking and even backlighting, then take your best shot.

📐 Resolution

I still hear a lot of confusion when discussing screen resolutions due to a simple lack of awareness. The most important thing to remember when shopping for resolution is PPI (pixels-per-inch). Any monitor can seem flashy when you slap a 4K label on it, but 4K means nothing if not considered with the physical screen size as well.

There are three important factors to remember when considering resolutions:

  1. Physical screen size (the diagonal measurement of the display. For example, 27 inches)
  2. Screen resolution (the number of pixels on the screen, measures on an x and y axis. For example, 1280 x 800).
  3. Viewing distance (how far away from the screen the viewer is. For a phone, this could be inches. For a television, this could be several feet).

1080, 4k, 5k, and 8k are all simply the total count of pixels on the screen. Consider a 4K monitor right in front of your face vs a 4K tv all the way across the room. They may have the same number of pixels, but the physical size and the distance from your eyes will play a huge role in your perception of the image displayed.

iPhones and retina screens looks so crisp because they have a very high PPI ratio. The entire goal of a retina screen is too have such high pixel density that the eye can’t perceive the pixels. The PPI of a non-retina MacBook is about 110. The PPI of a retina screen is about 220. Purchasing a monitor with a PPI in between 110 and 220 will cause blurring, half-pixel rendering, and general fuzziness (as illustrated by the gray line in this image when viewed at 100% size).

Blurry rendering

Photo credit: Bjango

Thus, it can be helpful to use a PPI calculator like this one to find out what PPI a monitor has. Our friends at Bjango put together this very helpful chart that shows the wide range of PPI possible from monitors on the market. (It’s a little outdated now, but still relevant)

A helpful comparison chart of monitor pixel densities

Apple partnered with and recommended the LG Ultrafine 4K Display (though it’s back-ordered worldwide currently thanks to COVID-19) and the LG UltraFine 5k Display (for about the same price as a MacBook Pro) but there are even some issues here, given that the 4K display was updated in 2019 with a slightly bigger physical screen size while maintaining the same pixel resolution—making it surprisingly less friendly to Retina screens than before.

My advice: If you have the cash for a 5K monitor with the right screen size, do it. If you don’t, purchase an affordable 27” 4K monitor and wait 1-2 years until the 5K monitors become more affordable.

💰 Price

This is obviously a personal choice or driven by the budget of your company. I observed three price brackets as I was researching:

  • $150–$250: Lower resolution monitors (110ppi) better for non-retina UI
  • $300–$800: 4K screens with varying levels of quality
  • $1,000+: 5k screens that are still somewhat new to the market

As I mentioned before, wait a year or two and most of those 5K screens will move down into the middle price bracket so you can afford that sweet, sweet retina goodness.

My advice: 5K screens will be half the price in 1–2 years. If your company can buy you one, the take the deal. Otherwise, it might be best to hold out.

🔌 Connection types

While almost all screens support HDMI connections now days, the DisplayPort has been the highest standard for computer monitor image quality (taking into account factors of resolution and refresh rate—more relevant to gaming and video production, but still relevant here). More recent HDMI standards are catching up, but you would need to double check that your monitor, your computer, and your HDMI cable are capable of meeting those new standards.

Some USB-C ports (such as found on the MacBook Pros) are capable of sending DisplayPort signals and can be used as such with the right cables.

You can read more about HDMI vs DisplayPort here.

Some of the newer monitors even have USB-C compatibility that allows the monitor configuration to be controlled by MacOS and the keyboard.

My advice: Don’t let this be a deal breaker. While USB-C compatibility can be convenient, I think color and resolution are much more important. Any of these problems can be solved with enough dongles and cables.

As previously mentioned, after weeks of research I purchased the Dell Ultrasharp U2720 Inch 4K. I’ll enjoy the color accuracy and brightness and deal with the resolution issues while I wait for the price of 5k screens to come down.

Further reading