When studying automatic, biometric face recognition it is import to understand what an appropriate baseline performance level is. Research has often shown that humans are actually not that good at doing face recognition, especially when comparing a photograph with a person in front of them.
Here is some more research in this area.
Experiments suggest that telling if two unfamiliar faces are the same or different is no easy task. … A new article in Applied Cognitive Psychology confirms these fears, suggesting that our real-world capacity to spot fakes in their natural setting is even worse than imagined.