One should not underestimate the physicality of light and the process of photography. I offer some Gedankenexperiments to illustrate matters that photographers don't need to think about but philosophers mulling about photography versus reality need as basic physics information. I'll leave the mathematics out.Going to have to disagree with you here - photography is light interacting with a sensitive surface and is therefore not a physical sample of the subject matter since the light is reflected by the surface and not generated by the surface (a photograph of a light source being exempted). When the light hits me and reflects towards the camera, it does not carry a piece of me with it and I am not diminished by it - rather, my clothing, skin and the physical characteristics alter the light to produce the image. Put it another way, if theoretically you could take an infinite series of photographs of me instantly, I would not disappear since you are not taking anything away from me.Quote Originally Posted by Maris View Post
Since there seems to be a lot of anxiety about reality I would offer the observation that there IS something particularly realistic about a photograph that separates it from virtually any other kind of representation. A photograph is generated when a physical sample of subject matter travels across space (at 300 000 Km/sec!) and penetrates the sensitive surface, lodges in it, and occasions changes that result in marks. This arrangement of marks, if it coheres as a picture, is a photograph.
Experiment 1: You are in a lighted room standing on very sensitive scales. The lights are switched off and instantly the scales show a loss of weight. Your weight stabilises at a lower level.
Experiment 2: Again you are standing on those scales but this time in a dark room. Someone a couple of metres away fires a Metz 45 flashgun at you. The scales indicate an increase in your weight and then a decrease back to your original weight. If you are a phosphorescent being (unlikely) the full return to original weight might take some hours!
Experiment 3: Gold is yellow.
These experiments indicate that the light that illuminates things actually becomes part of those things. Light is a quantum entity with a particle aspect called a photon and a wave aspect manifest as an electromagnetic field. It's not a shower of tiny bullets as Isaac Newton thought.
Experiment 3 sharply illustrates an apparent anomaly. If photons are tiny billiard balls that reflect off hard things then how come a beam of white light hitting gold comes back yellow? For a photon to discover gold is yellow it actually has to do something impossible in classical physics. It has to penetrate metal. Quantum physics explains photon tunnelling and how photons penetrate gold (billions of atoms deep even) then become part of the gold and later get re-emitted in a changed form. Re-emission can be spoken of in terms of elastic and non-elastic scattering. We see the "changed form" as yellow light coming back where white light went in. If light is thought of as a wave instead of a photon then an analogous process proceeds and the end result can be quantifiable as re-radiation. In informal speech scattering and re-radiation are subsumed in the term reflection.
The serious point here is that the light collected by a camera really was a physical part of the substance of the subject matter. The classical mind-picture of reflection as light "bouncing" off the external surface of things is not what actually happens.
Another point missed by Van Lier and other philosophers who think about (but do not do) images, imaging, and possible connections to reality is that there is a whole class of image making procedures that are utterly physical in their workflow and their output. These include life casts, death masks, brass rubbings, papier-mache moulds, coal peels, photographs, and even footprints in a sandy beach. All of these things are unaguably embedded in reality and there is no philosophical credibility in vaporising about the opposite. Where things go off the rails, in the particular case of photography, is mistaking it as a species of painting or drawing; just with some mechanical aspects thrown in. The great philosopher Ludwig Wittgenstein pointed out that many of the conundrums of philosophy originate from getting the original assumptions wrong, following up with the wrong words, and ending up with a labyrinthine confusion of impenetratable text. Henri Van Lier would not be the only one to have run this hazard.