Manual and automatic exposure metering systems integrated into the camera have long since been standard equipment – for professional cameras too. Thanks to innovations such as matrix metering and a pre-flash function for determining reflection characteristics, current TTL measuring systems (TTL = through the lens) are ideally suited for assuring good exposure in particular with dynamic subjects.
The success rate is quite high and deviations can frequently be corrected with digital post-processing, although this is always associated with qualitative losses. These systems are still imperfect. Fundamentally, every TTL measurement has a design-related disadvantage: It measures light reflected by the subject, not the light which strikes it.
Read more about this issue in light//story02 from HENSEL.