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Second screen on the notebook: More space for programs, browsers, chats
Photo: Franca Quecke / DER SPIEGEL
Ever since I started working with two, sometimes even three screens in the office, I've found it increasingly difficult to do without them when I'm on the go or working from home.
My everyday office equation: more screen real estate = fewer decisions = more peace of mind.
That's why I've been looking for a mobile monitor for a long time that expands the screen area of my notebook when I'm not working in the office.
This way I could keep an eye on my open e-mails, my texts and other documents in my home office or on long train journeys - and save myself the hassle of opening and closing tabs in the browser.
What must an on-the-go screen be able to do?
Now I have tested five such devices.
What they all have in common: Except for the Viewsonic, which has a 16-inch display, they all have 15.6-inch displays and are reasonably light.
They also have a Full HD resolution, i.e. display 1920 × 1080 pixels and work with an eye-friendly refresh rate of at least 60 Hertz.
They also come with an integrated stand and/or cover that can also be used as a stand.
It was also important to me that they can be connected via USB-C, because not only the image data, but also the power required for operation can be supplied to the screens via this connection.
Convenient as it is, it's important to remember that connecting a portable second screen in this way will share your laptop's battery.
This can drastically reduce battery life.
A solution that protects the notebook battery is the ZenScreen MB16AP from Asus, which has its own battery that is sufficient for a service life of up to four hours.
That's enough for at least a short search in a library.
With two USB-C sockets each, the test models from Lenovo and Viewsonic enable the monitor – connected to a power supply – to also supply the notebook with power.
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A software installation is not necessary for any of the screens, all work on both Windows 10 notebooks and MacBooks via plug-and-play.
Only if you want the monitors to switch automatically between portrait and landscape format does it sometimes have to be installed.
A USB-C cable is included with all tested models, the tested Viewsonic also has an HDMI connection.
Philips 16B1P3302
My first test object is the Philips 16B1P3302.
Its matt surface ensures that lamps or the sun shining through the window are not perceived as annoying reflections.
However, it is not bright enough to illuminate against the blazing sun.
It reproduces colors realistically, but quite pale. This impression is intensified when you look at the screen at an angle.
The base can be continuously adjusted from 0 to 90 degrees and provides enough stability so that it usually stands securely on the small fold-out tables on train journeys without jerking or rattling.
The control buttons appear rickety and are unfavorably placed at the back of the stand.
A 1.8 meter long Y-cable from USB-C to USB-A and USB-C is included.
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The Philips is the only monitor in the test that offers a refresh rate of 75 Hertz, which ensures a somewhat clearer image reproduction when scrolling than the 60 Hertz models.
There is a connection for headphones and quite extensive control functions.
A gray felt cover is included for transport.
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Signs of wear are already visible after the test
Photo: Franca Quecke / DER SPIEGEL
Flop:
With a weight of around one kilogram, the Philips is a bit heavier in your pocket than the competition.
The Philips logo on the front already shows signs of wear after the short test phase, although the screen was mostly in its felt cover in my backpack.
ASUS ZenScreen MB16AP
During the test on a train ride, the Asus screen caused trouble: when the train jerked, it sometimes went off and turned on again a short time later.
The reason: The supplied one-meter-long USB-C cable cannot be plugged into the ZenScreen MB16AP's connection socket firmly enough.
This makes the connection sensitive to wobbles.
The problem did not occur with other USB-C cables.
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Loose connection: The supplied USB-C cable from Asus does not reliably connect the monitor and laptop
Photo: Franca Quecke / DER SPIEGEL
Unlike the other screens tested, the ZenScreen has an integrated battery.
To charge it, a power supply unit with a USB-A socket and an adapter for the supplied USB-C cable is included.
A USB-C power supply would be more practical.
You can choose in the menu whether you prefer to use the or draw power from the laptop.
With the latter, it can be navigated quite intuitively and quickly with two buttons on the front.
I like the design of the ZenScreen with its narrow frame.
The image reproduction convinces with strong contrasts and radiant colors.
Unfortunately, the screen is very reflective.
A foldable imitation leather transport case is included, which also functions as a stand, but is not infinitely adjustable.
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If you don't have the foldable protection at hand, you can set the device up using a pin that is inserted through a hole in the housing.
A suitable ballpoint pen is included in the scope of delivery, but you can also use other models.
In this way, the screen is stable in both portrait and landscape format, but its inclination cannot be varied.
At 850 grams, the ZenScreen is one of the lighter mobile monitors.
It is very practical that the Asus has its own battery, i.e. it does not drain the notebook, tablet or smartphone to which it is connected.
Flop:
The USB-C cable proved to be of little use in our test.
The screen is extremely reflective, which is why fingerprints shimmer on the surface.
In strong light, for example when the sun shines directly on the monitor, you can see your reflection on the screen, but less so e-mails and documents.
AOC I1601P
A USB-C connection socket, a button for the menu, a one-meter-long, very stiff Y-cable with USB-C and USB-A connection: the monitor from AOC has a minimalist design.
The menu control of the device is completely different, which requires patience because you have to wait for a repeated blinking to select a menu item and call up the menu again after each change.
The AOC l1601P is the simplest, cheapest and, at 800 grams, the lightest screen in the test.
You can tell by looking at it, the glossy black plastic of the case looks cheap.
A magnetic cover is included as a standing aid, which only allows a stable viewing angle.
The quality of the screen display is usable as long as you set medium contrast and brightness values.
If you go beyond that, fonts quickly become illegible.
It is pleasing that the display is matt and thus reflections and reflections are reduced.
Unfortunately, it depends heavily on the viewing angle, so it is only easy to read if you look at it perpendicularly.
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Quick start, pleasant anti-glare display.
Flop:
People who are obsessed with tidiness might be bothered by the fact that the USB cable doesn't quite fit into the socket.
The frame is wider than the other devices, the supplied case only protects the front.
With frequent transport in a backpack, the back is accordingly prone to scratches.
Lenovo L15 monitor
First of all, a commitment: Both my private and my work laptop are Lenovo products.
So maybe I'm a bit biased.
But for my home office needs, the L15 worked well.
I like the fact that it's ready to start quickly, and that I can quickly adjust brightness, contrast and the low blue light function, which is intended to protect my eyes, using three buttons.
Unfortunately, the plastic buttons are sunk deep into the case and have to be pressed quite hard.
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With the Lenovo, the height can be adjusted to a certain extent
Photo: Franca Quecke / DER SPIEGEL
In addition, the L15 has an integrated stand that allows a tilt angle of 0 to 90 degrees and even a height adjustment of up to ten millimeters.
There are USB-C sockets on both sides of the stand.
So you can connect a notebook, tablet or smartphone and a power pack for power supply at the same time.
In contrast to a quite elastic and one meter long USB-C cable, the latter is not included in the scope of delivery.
Lenovo's display also reduces annoying reflexes and reflections with an anti-reflective coating, and like all the screens in the test, it is not very bright. The color reproduction is successful and the colors don't change noticeably when you look at it from the side.
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matte display, narrow bezel, quite light at 860 grams.
Versatile adjustable stand.
A dark gray felt sleeve is included.
flop:
Other devices offer significantly more setting options in their on-screen menus.
The display quality is solid, but I am used to stronger contrasts from my laptop.
Viewsonic TD1655
The Viewsonic TD1655 is lavishly equipped: It is the only one in the test that has a touch display that the manufacturer describes as scratch-resistant.
It also comes with a digital pen that you can use to write and draw on the screen.
In addition, the device has two built-in loudspeakers, which, however, are only suitable as an absolute emergency solution,
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The Viewsonic is unusually well equipped with jacks
Photo: Franca Quecke / DER SPIEGEL
In addition to two USB-C sockets, a mini HDMI connection and a headphone socket are available.
An HDMI cable, a USB-C cable and a USB-A to USB-C cable are also included.
There is also a power pack in the box.
The image display is the best in this test: the Viewsonic reproduces colors very strongly and delivers good contrasts.
The glossy surface of the display is annoying, so you should stay away from bright light sources.
On the back is a fold-out stand that allows the screen to be tilted up to 60 degrees.
In addition, a magnetically adhesive cover is included in the scope of delivery, which can also be used as a non-slip base.
A small joystick on the back of the device allows for flawless navigation through the beautifully designed on-screen menus.
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The Viewsonic is lavishly equipped with functions and connections in every respect.
Useful: it recognizes whether it is being powered by the mains adapter, a laptop or a smartphone and adjusts its brightness - and thus the power consumption - accordingly.
Design, materials and workmanship make it appear more valuable than the competing products.
Bad:
the screen is too reflective and the supplied cover only protects the front.
After the short test period, scratches and wear and tear are already visible on the back.
With a weight of almost one kilogram, the Viewsonic is one of the heavier devices.
Conclusion
If you work in a well-lit office or often outdoors, you should use matte screens like the Lenovo L15.
With the Philips 16B1P3302 I have that for a long time
I found the connection cable to be pleasant because it gives me more flexibility when setting up than short strips.
Of course, you can also buy such a cable later for little money.
The ZenScreen MB16AP from Asus is recommended if you want to use the mobile second screen regularly when away from a power outlet, because it doesn't drain the laptop's battery thanks to its own battery.
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