Talk to a traditional portrait photographer and they will most likely tell you that any lens focal length less than 85mm equivalent is not a true portrait lens. Reasons given are usually focused on controlling distortion and using compression and subject isolation.  These are all extremely valid and sensible reasons…lets call them rules…that serve as an excellent guide to getting awesome people shots.

However as a street photographer, i am not always looking for the traditional portrait shot, nor am I working in the traditional way that a portrait photographer would work.  Shooting street portraits there are always a range of factors in the environment around you that I have no way of controlling.  I also am limited in the amount of gear that I carry around with me all day (self imposed but who wants to walk 10-12km carrying a bag full of gear?).