It will determine the exposure value to set with the cameraExposure meterEven if it is cheap, you can only buy it from the latter half of the 10,000 yen range, but if you have an exposure meter for ...

Smartphones are now such commonplace devices that it's easy to forget what miraculously clever things they are. The things we used to quaintly call "telephones" are now festooned with sensors, cameras ...