PERFORMANCE: While the Microsoft Lumia 640 garners some high scores, many others score better. This phone could still be a good budget choice if you can get it at a good price or if you need only a basic smartphone. Ergonomics on the Lumia 640 were good. Some areas of this phone may not be the easiest to use but you should be able to get used to it. Call quality and convenience on the Lumia 640 were not the best but they were very good. Sound while on a call was very good in a quiet room and with background noise. Your sound quality will vary due to many factors including background noise, if you are moving between cell towers, the quality of the phone on the other end of the call, and the quality of the cell tower and antenna.
DURABILITY: After 50 drops in the tumbler, our experts rated it as very good. The phone had some scratches and the back cover was dented but it was still in good working condition. After our more strenuous 100 drops in the tumbler the screen and body proved they can take a serious tumble. Our experts rated it as excellent. .Overall, it was in good working condition.
PORTABILITY/BATTERY: The 5-inch screen on the Lumia 640 comes in a body measuring 5.6-inches tall, 2.9-inches wide, 0.4-inches thick, and weighs 5.1 ounces. Those measurements mean the phone is shorter and lighter than most. Its battery is removable but the phone doesn't support wireless charging.
CAMERA: The Lumia 640 has a single 8-megapixel camera. The camera does not have optical image stabilization so handheld photos in low light may be blurrier than cameras with optical image stabilization. Overall the camera performance was only fair, well below that of many models but still good enough for casual photo taking. Images are evaluated on high quality 24-inch LCD displays. The test photos are taken in a brightly lit studio and outdoors on a sunny day. In the viewing tests the images were rated only fair overall. These image results are noticeably not as good as most smartphones for color quality, exposure level, sharpness (noticeable over sharpening), and image noise. The Lumia 640 comes with a 0.9-megapixel selfie cam. Overall the selfie camera quality was only fair, well below that of many models but still good enough for selfies viewed on social media.
DISPLAY: Overall the display quality was good, The display resolution was barely high enough, close to 300dpi, so you see a smooth, but not very crisp image. The display showed some glare in daylight. Readability outdoors is a combination of brightness, measured in candelas per square meter, and reflectivity. The readability rating was good. Brightness was a little dim for outdoor sunlight at 380cd/m² and reflective glare was slightly noticeable.
