Are identity photographs, of the form commonly used for things like a bus/rail pass or membership card considered to be "special category data" within the meaning of the UK's Data Protection Act 2018?
It seems to me they would almost certainly be, even if not processed for biometrics currently because they are likely to cover at least race, ethnic origin and frequently also religion. Health may also be covered by such photographs, if for example an individual has visual signs of health issues in/around their head.
I believe the above points should be sufficient to conclude that identity photographs almost always count as special category data, but given that a well taken identity photograph could trivially be used to extract biometric information I can't really see how that case also wouldn't apply. This seems to cover even the retention of printed copies of photographs.
Is my reasoning here correct? Is there anything concrete to support this interpretation? Given the substantially raised barrier to using such data how can an organisation legally justify their use of ID photographs on membership cards (and a corresponding record retained by them)?