Monitor light bars: light for keyboard and desk

When a desk needs a monitor light bar

At a screen workstation two things get in each other's way: the bright display and the desk surface in front of it. A classic desk lamp takes up space, casts shadows from the writing hand and is easily reflected in the panel. A monitor light bar solves the space problem because it sits on the top edge of the screen and takes up no desk surface.

It makes most sense in three situations. First, when keyboard, notepad and mouse lie in the same area and you look down without light falling on the display. Second, in the evening, when the room is dark and the display remains the only bright surface. Third, when the desk is small and there is simply no room next to the monitor for a lamp base. A more detailed assessment is in the guide When a monitor light bar makes sense.

It is less suitable if you need a lot of light for handicrafts, drawing or modelling and want to swivel the light freely. In that case an adjustable arm or a clamp lamp on the desk keeps the advantage. The overview of desk lamps shows which lamp types exist for the desk overall.

Asymmetric optics: why the bar does not dazzle

The difference from a lamp laid across the desk lies in the light distribution. Monitor light bars shine asymmetrically: forwards and downwards onto the desk, not vertically onto the screen surface and not into your face. According to the manufacturer, BenQ calls this technology Asym-Light. For the BenQ ScreenBar Halo 2, the listing gives an 18-degree anti-glare angle that is meant to prevent reflections on the monitor. For the Quntis monitor light bar 40 cm in white, Quntis describes, according to the manufacturer, a 45-degree asymmetric light output.

Note that such figures are manufacturer claims. How well glare-freedom works on your monitor depends on seat height, viewing angle and the gloss of the desktop. A glossy surface can throw light back towards the eye despite good optics. We have not measured anything and therefore only describe what the documents state.

The second effect concerns contrast. A bright screen in a dark room forces the eye to keep readjusting as soon as you look at the keyboard. A brightened work area reduces this difference. More on the interplay of screen and surroundings is in the guide Working in an eye-friendly way.

Putting brightness and colour temperature into context

Two kinds of figures circulate for monitor light bars: lumens and lux. Lumens describe the luminous flux of the lamp, lux the illuminance that arrives at a point. For the bar, lux is the more useful figure, but only with a distance. Without the height above the desk the value says little, because illuminance falls off markedly with distance.

For the BenQ models the figures are comparatively specific. According to the manufacturer, BenQ gives for the BenQ ScreenBar Pro more than 1,000 lux in the centre at a height of 50 centimetres and a 500-lux area of 85 by 50 centimetres. For the BenQ ScreenBar Halo 2 the same values apply according to the data sheet. For the BenQ ScreenBar monitor lamp, the listing gives 500 lux over 60 by 30 centimetres; we do not have a manufacturer document for it. The values are therefore not directly comparable, because the area and the source differ.

For colour temperature the ranges overlap. The BenQ ScreenBar monitor lamp, the Halo 2 and the Xiaomi bar give 2,700 to 6,500 kelvin, for the ScreenBar Pro the range is missing, and the Quntis white version gives 2,700 to 5,000 kelvin according to the manufacturer. What the kelvin values mean in daily life is explained in the guide Colour temperature and kelvin. As a rule of thumb: neutral to cool tones suit concentrated daytime work, warm tones suit later hours.

Note on daylight: if you also want to use a lamp against the winter blues, a monitor light bar is not designed for that. Light therapy also does not replace medical treatment.

Controls, power and clamp: the practical criteria

Monitor lamp, Halo 2, Quntis and Xiaomi are powered by USB; for the ScreenBar Pro the source gives no power supply. This saves a socket, but has a limit: not every port supplies the same amount of power. For the BenQ ScreenBar Halo 2, BenQ gives, according to the data sheet, USB-C with up to 15 watts. The Quntis Monitor Light Bar 41 cm is powered, according to the listing, via a 2-metre USB-C cable at 5 volts and 1 amp. The BenQ ScreenBar monitor lamp works via USB-A according to the listing. Before buying, check whether your monitor or computer has suitable free ports.

There are three control concepts. Touch on the bar only needs a reach to the monitor. A remote control or controller sits on the desk: the BenQ ScreenBar Halo 2 comes, according to the listing, with a cordless controller with a display and up to three months of battery life, and the Xiaomi Mi Computer Monitor Light Bar with a cordless 2.4-gigahertz remote control according to Xiaomi. Finally, a sensor takes over the switching itself: the BenQ ScreenBar Pro detects, according to the listing, movement up to 70 centimetres and switches off after five minutes without presence.

The clamp decides whether the bar fits at all. The ranges differ noticeably: the listing for the BenQ ScreenBar monitor lamp gives monitors 1 to 3 centimetres thick, the Pro 0.43 to 6.5 centimetres according to the manufacturer, the Halo 2 0.43 to 6 centimetres according to the data sheet, and the Xiaomi bar up to 32 millimetres according to the manufacturer. With very thin displays, according to Xiaomi, some support may be needed when adjusting. You should check curved monitors and unusual rear panels, webcam position and housing shape against the dimensions beforehand.

Monitor light bars compared: the data side by side

The table sets out six bars with the values that appear on the respective product pages. The source is in the last column; manufacturer means that a manufacturer document was evaluated, listing stands for information from the retailer listing. Empty fields mean that the product page states nothing on the point.

No ranking follows from the table. It shows rather where the documents leave gaps: for the Quntis bars lux figures are missing, and for the BenQ ScreenBar monitor lamp a manufacturer document is missing. What is empty in the table is not on the respective product page and is not filled in here.

Which bar suits which workstation

The following assignments are assessments from the documents, not hands-on verdicts. They start from the need.

• You do not want to keep readjusting: the BenQ ScreenBar Pro switches itself on and off by ultrasonic sensor according to the listing. Suitable if you often leave your seat and come back.
• You like to adjust from the desk: the BenQ ScreenBar Halo 2 with its cordless controller suits you if reaching to the monitor is a nuisance. It also has a back light that is meant to soften the contrast with the wall. Details are in the data check on the ScreenBar Halo 2.
• You want the simple option: the BenQ ScreenBar monitor lamp is the bar with touch control and auto-dimming. An alternative to the wireless models if reaching to the bar is enough for you. There is no manufacturer document for it.
• You need a remote control without BenQ: the Quntis Monitor Light Bar 41 cm lists a remote control and touch control. An alternative to the BenQ bars if you want a remote control. Quntis offers several similarly named light bars, so check the exact variant.
• You have a light-coloured desk: the Quntis monitor light bar 40 cm in white comes in white and, according to the manufacturer, has a front and back light that can be adjusted separately.
• You want a remote control and a metal housing: the Xiaomi Mi Computer Monitor Light Bar gives, according to Xiaomi, a width of 448 millimetres and five watts. According to Xiaomi it is not recommended for laptops.

Planning at the desk: monitor light bar plus room lighting

A monitor light bar does not replace room lighting. It brightens the work area, but the room behind stays dark if no other light is on. Combining it with a dimmed ceiling light or a floor lamp behind you reduces the brightness gradient between display and surroundings. The back light that some models include takes over part of this job, but does not replace room lighting.

For paper documents, it is worth looking at illuminance and position. The guide Lumens for desk lamps puts into context what order of magnitude of lumens a desk lamp needs. How monitor light bar and room lighting complement each other for your room size is worked out by the lighting calculator.

Cable routing is also part of the planning. The bar hangs on the monitor, and the USB cable runs along its back to the port. With monitor arms or wall mounting you should allow enough cable length so that the screen can still be adjusted. If you often turn or tilt the monitor, also check whether the clamp stays secure and whether the weight of the bar tips the monitor head.

Another point is the webcam. Many monitors have a camera at the top centre, and a bar can cover it or intrude into the picture. The listing for the BenQ ScreenBar Halo 2 mentions a mount that is not meant to cover webcams. Whether this applies to your monitor can only be settled with dimensions and a photo of the top edge. The same goes for notebooks: according to the manufacturer, Xiaomi does not recommend its own bar for laptops, and for other models too the clamp is designed for standalone monitors.

Finally, the question of the overall picture of the workstation. If you sit at the screen for many hours a day, you benefit from a colour temperature that suits the time of day and a brightness that can be adjusted without fuss. The simpler the controls, the more likely they are to be used. That is an assessment from the design, not a measured finding.

Other options besides the bar, such as clamp lamps and table lamps, are in the desk lamps category. Before deciding, a short checklist helps: measure the monitor thickness, check the USB port, note the webcam position and decide whether you prefer touch, remote control or sensor.