eggboard (315140) writes "A tintype is a form of wet-plate collodion photography, which requires exposing a metal plate covered in fluid chemicals within a short period of time after applying the emulsion. The process is receptive only to blue light, which tends to emphasize wrinkles and capillaries. The results are both gorgeous and unforgiving, the opposite of the selfie that tries to blur, hide, or present the subject in the best light. It may be old fashioned, but more and more shops have sprung up to offer slow photography. One in San Francisco has produced piles of prints, but is shutting down as its owners pursue other endeavors."
Link to Original Source