Offering a solid design, decent display and confirmed to receive an update to Windows 10, the Lumia 640 is one of the best affordable smartphones available to businesses using Microsoft services.
Affordable, solid design, decent screen, Windows 10 ready
Processor is showing its age
Screen: 5in, 1280x720, 294ppi, TrueColor, ClearBlack, IPS
Processor: 1.2GHz quad-core Qualcomm Snapdragon 400
Storage: 8GB, microSD
Camera: 8MP, 1/4in, f/2.2 rear camera with LED flash and 0.9 MP wide angle f/2.4 front
Motorola radically changed the budget smartphone market in 2013 when it unveiled the first-generation Moto G.
The Moto G featured internal specifications traditionally seen only on smartphones close to £100 more expensive, and was in many people's minds, including V3's, the first affordable smartphone to offer truly decent performance.
Since then smartphone makers have been rushing to up their budget game. To date, however, Microsoft's Lumia smartphones have been the only examples capable of matching Motorola's fantastic value for money offering.
The Lumia 640 was unveiled at MWC in Barcelona in March alongside its plus-sized sibling the Lumia 640 XL, and is Microsoft's latest affordable handset designed to continue this effort.
Design and build
The Lumia 640 has a similar design to past Microsoft handsets and comes with a detachable, smooth-finish polycarbonate chassis that grants access to the microSIM and microSD card slots.
The detachable covers, while tricky to remove, are a welcome addition and make it easy to change the handset's colour or replace the cover should it get damaged, although our hands-on suggests that damaging the Lumia 640 to the point that the chassis needs replacing would require a fairly big accident.
Despite being made of plastic and being prone to picking up dirt marks, the white Lumia 640 we reviewed was sturdily built and easily survived an encounter with a hardwood floor scratch and crack free.
Additionally, while slightly slippery-feeling, the Lumia 640 is fairly comfortable to hold. Featuring 141x72x8.8mm dimensions and weighing 145g, the Lumia 640 fitted neatly into our hand and never felt unwieldy.
Screen technology is usually the first area that gets cut when designing affordable smartphones. This was showcased this year by the Motorola Moto E and Lumia 535 which, while good value for money, featured below average displays.
However, testing the Lumia 640's 5in 1280x720, 294ppi TrueColor, ClearBlack, IPS display we were surprised how good the screen was, especially when considering the handset's SIM-free £170 price.
Colours on the Lumia 640 are vibrant, but not oversaturated, and icons and text are sharp and constantly legible, even when doing things like reading web pages in the desktop view. Brightness levels are also decent, and overall we had no serious concerns with the Lumia 640's display.
The Lumia 640's above average, for the price, screen is mainly down to the inclusion of ClearBlack. This is a custom technology designed to let screens display deeper blacks and offer better viewing angles.
It works by reducing the amount of ambient light the screen reflects using twin filters that polarise incoming light and stop it bouncing back into the user's field of vision. This stops the screen becoming reflective in direct light and lets it display deeper blacks.
The screen's performance in adverse lighting conditions is further aided by the Lumia 640's sunlight readability enhancement technology.
There's also a Lumia colour profile tool for those who want to tweak the Lumia 640's colour calibration. The tool lets users pick between pre-set standard, vivid and cool settings or create their own using an advanced mode.
The advanced setting lets users manually change the Lumia 640 screen's colour temperature, saturation and tint.
Operating system and performance