I’m not interested in people in the portrait sense, in the individual sense. I’m interested in people as part of the pictures and as themselves, but anonymous.
Between 1938 and 1941, Walker Evans took photographs on the New York subway, using a concealed (and presumably pre-set) 35mm camera operated by a remote control cable. Evans’ career as a whole, and the subway photographs in particular, may be seen as an attempt to appropriate the rhetoric of official, institutional photography – the police mug shot and so on – and apply it to other ends. In his subway project, Evans was trying to produce anonymous portraits, the complete antithesis of the celebrity glamour shots he dismissed as mere photographic name-dropping.  The resulting images are often praised for their intensity or psychological acuteness. Evans himself claimed that they show the subjects in naked repose, when the guard is down and the mask is off. 
I would argue that they actually create the opposite impression. Evans' subjects are trying to erase any expression of individuality to reduce their vulnerability to the gaze of strangers (strangers like Evans). As a result, the pictures are highly repetitive - dare I say that they are actually quite boring - precisely because everyone is equalized within them. There are no tell-tale gestures, and no conversations. In short, no-one is actively communicating with anyone else, least of all with Evans. Everyone is in the same null state.
Far from seeking to demonstrate his empathy with or understanding of his subjects, Evans wanted to prove that the camera can be made not to think and not to translate its operator’s emotion, and he described his purpose as follows.
It might seem that Evans was attempting to attain the state of mind and technique of the ideal spy, but if so, then the ideal in question is a modern one. It was not, for example, that of Gerolamo Vano or his seventeenth-century Venetian masters, who did not associate objectivity with machines (or indeed with science).  For them, the judgement of God was the model of objectivity, which meant that truth was rooted in a consciously directed and morally-informed gaze. In the law courts too, truth was closely associated with presence, with a rational consciousness, since conviction depended largely on eyewitness testimony. It is only very recently that forensic evidence (interpreted by expert witnesses who have no direct knowledge of the crime) has begun to displace such testimony. Similarly, the information provided by Vano always depended on the physical presence of an informant.
Photography as it is usually practiced has more in common with this older conception than Evans’ comments might imply. It is well known that the authority of a photograph comes from the fact that its subject must be present in front of the camera at the moment of exposure. What is less frequently acknowledged is that, in most cases, the fact that the photographer was physically present to press the shutter is also critical: not only, ‘This happened’, but ‘I was there when it did’. The photograph is the result of an act of perception (even if it involves a transformation of that act). Even more importantly, it is the result of a choice.
The impersonal ideal that Evans was apparently reaching for has apparently been fulfilled with the invention of the closed-circuit television camera and/or digital webcam. Because this machine records (or transmits) continuously, without interruption and hence without the need for choice, it eliminates the need for human intervention beyond its initial activation. But I imagine Evans’ goal was less to obtain a purely mechanical image than to reduce himself to a machine: not to eliminate consciousness but to transform it.
Not only, ‘This happened’, but ‘I was there when it did’.
 Quoted in Mia Fineman, ‘Notes from Underground: The Subway Portraits’, in M. M. Hamburg, J. L. Rosenheim, D. Ekland and M. Fineman, Walker Evans, 2000, p. 108. There are various redactions of the subway pictures. The early versions severely crop the negatives to show only the head and shoulders of the subject; the later ones include more of the extraneous detail around them, a change that probably shows the influence of younger photographers like Robert Frank upon Evans.
 Quoted in Walker Evans at Work: 745 Photographs together with Documents Selected from Letters, Memoranda, Interviews, Notes. With an Essay by Jerry L. Thompson, 1982, p. 152. James Agee made the same claim in his introduction to the book version of the subway pictures.
 Both quotations from an unused preface to Evans’ published collection of the subway photographs, reproduced in ibid., p. 160. This manifesto recalls Walter Benjamin’s claim that Photography prepares the salutory movement by which man and his surrounding world become strangers to each other … opening up the clear field where all intimacy yields to the clarification of details.
 However, the Italian word for ‘lens’ is the same as the adjective ‘objective’ [obiettivo] and in the early seventeenth century, Galileo’s discoveries in astronomy depended on recent improvements in the optics of the telescope, which he helped bring about in co-operation with Venetian glassmakers. The ‘realism’ of seventeenth-century painting also depended partly on the use of the camera oscura, as David Hockney has recently argued.