So, reading ones finger is acceptable. A study has shown that 3 out of 4 employees reject the idea that using fingerprint to identify one's identity makes them feel like a criminal. To the contrary, they support the use of fingerprints to counter fraud and cheating. Face recognition is the second most popular method of biometric ID behind fingerprints. People are used to CCTV cameras, and do not seem particularly concerned about having their picture taken.
Face recognition requires well-structured lighting conditions.
The slightest variation in illumination can throw the performance of the system way off. Hence, it is only used for indoor environments or a very well controlled and structured outdoors environment, which can be expensive and in some cases, unrealistic. Trial tests are limited and not well advertised by face recognition manufacturers. Tests point to the fact that variations in lighting and contrast can compromise the face recognition system performance. The face recognition offers the most competitive advantages and offers an alternative to fingerprint recognition, since it requires no cooperative users.