This article was published in the Spring 2012 of SMACK magazine.






The Theory of Continuous Change as a Way of Describing the Distinctions between the Divergent Worlds of Analogue and Digital from a Photographic Perspective. 


There is a conversation that exists in photographic circles about the merits of film versus digital. It is not a subject to which you may have given much thought but it is one that I and many of my colleagues in photography have discussed at length and never concluded. I think the difficulty we have settling this disagreement is due to a failure to recognise the terms of the battle rather than a failure to recognise which is the better medium. I believe the argument should resolve on the subject of humanity and not on photography itself. The argument I have set out below could be applied to many different media where our increasingly digital life encroaches on our more intuitively chaotic, visceral, human nature. And finally, I have tried to come up with a definition (that of Continuous Change) which can be used to describe the fundamental differences between analogue and digital capture. 



In computer terms there is a difference between a transistor involved in the working of a microchip and the valve used in old fashioned radios and audio equipment. A computer chip uses a binary series of on/off commands to carry out its work, whereas an analogue transistor allows the expression of continuous change. This is best expressed by the divergence between the way the human brain and a computer chip works. A human brain processes in a state of continuous change using chemistry and billions of neural connections (CC) and so is able to intuitively adapt to various environments and tasks whereas a computer chip is binary and only capable of carrying out certain tasks (and reacting to particular environments) for which it was designed. The fundamental variation between film and digital capture is that film is an analogue process and the way it captures light comes from a process of continuous change whereas digital recording of light involves a binary process where aspects of each pixel are either on or off. 


To be clear about the media we are discussing; generally speaking film is a piece of see-through plastic with a thin coating of silver halide (SH) crystals (some films differ marginally). These crystals change when exposed to light in a non-binary, free-form way. That is to say, the crystals are neither ‘on’ nor ‘off ’, rather they are different the one from the other to an infinite degree as a result of the light that each crystal has been exposed to. In addition SH crystals are arranged at random across the film base. In the case of digital photography the sensor is a light sensitive plane which is ’x’ pixels wide by ’y’ pixels high x bit depth (this is what is known as ‘resolution’). Bit depth is described as the ability of a pixel to accurately represent colour and brightness on an increasingly accurate scale; 8bit, 16bit, 32bit and so on. In digital photography every aspect of the light recording plane is ascribed a location and a binary value. So the core difference between film and digital capture is that the structure of the light capture plane of film is random whereas the digital plane is ordered. 


The same rules apply to sound recording, which helps to illustrate this contrast. An area in which sound and light recording are directly analogous is what happens at the edge of light capture, i.e. what happens when light (or sound) peaks or troughs beyond the recordable levels of the film or sensor. In film there will be a continuous decline of reciprocity at either end of the scale until what levels of light there are will be unrecordable with a smooth, organic decline at either end of the scale. Digital sensors follow this curve too but at some point the recordable data will cut out. This is known as ‘clipping’. To help envisage this try to imagine a stream which runs over sand into the sea (which in this case represents noise or light ‘oblivion’ i.e. too much or too little to record). The ‘analogue’ stream will divert, change course, adapt as the sand and waves conspire to alter the terrain it flows over but the ‘digital’ stream may follow fine pathways but it will always chase the same runnels into the ocean. To sum up, in the analogue world either end of the recordable scale is arrived at with nuance and natural decline whereas those areas of oblivion are reached with a command “off!” in the case of digital. 


Following from this, a friend of mine who is a sound recordist, made the point that both analogue and digital sound capture have superficially comparable properties in the mid ranges but it is at the peaks (or troughs) of capture where the variations are most marked. When digital sound capture peaks out of recordable range it sounds fractured and unnatural but the peaks and troughs in an analogue recording can sound wonderfully weird and beautiful as evinced by countless contemporary musicians who “tune their amps to 11” to exploit this property. This is true of analogue (film) light capture where 


can all be beautiful because of the principle of ‘Continuous Change’. Because film records light with random silver halide crystals that do not follow a formalised binary recording process the many nuances of light and movement can be captured harmoniously creating organic tones and forms. Many of these qualities may not be readily visible to the human eye unless they are coaxed out of the mess of altered silver-halide crystals by a skilful technician. 


There is also a discussion to be had about the comparable ability of one medium over another to accurately render colour this being contrasted by film’s chemical approach and digital’s channeled colour process but as I want to describe my theory of CC for the purposes of art and not pure science I am not going to go into those arguments here. Indeed all that can be said about black and white film can be said about colour film versus digi just as well with the one caveat that various films (just as monochrome films) have different response rates to colours which rather ‘locks’ a certain look into the qualities of the film which digi does not. 



If you shoot on black and white film and print as a silver-gelatin print then you will create a print that represents light being captured in a state of continuous change which extends through the whole process – from shot to print. If, on the other hand, you shoot on film and print digitally then one of the three required processes (exposure, scan & print) will have CC properties but the following two will have binary properties. What this means to the final print is that the resulting printout from a straight digital capture may appear to be smoother but will be devoid of any of the sometimes imperceptible qualities of an exposure captured on organic, infinitely changeable film. I believe that there are qualities in film that we don’t pick up on consciously but which our brains draw on when we view these images. Indeed it has been said that the quality achievable from scanning film is limited to the quality of the best scanners available. Who knows what amazing depths of CC we will be able to discover in analogue images in the future? 



When a film exposure is digitised in a film scanner it follows that the best scan possible is achievable with the best equipment and the best technique. However, the limitations of digital capture still apply and can impair naturally rendered detail in the peaks and troughs however there will be much of the ’feel’ of film in the resulting image which will convey the chemical or analogue nature of the organic medium. For this reason alone scanning film is very valuable because, despite the digital limitations (as already discussed) much of the native quality (especially tonal curves and response rates of the film to the colour spectrum) is transferrable to a digital file. 


In a way Continuous Change is merely a way of explaining the distinctions between analogue and digital capture – both methods have their benefits and drawbacks; the ability of digital photography to shoot in low-light, the versatility of varying ISO and the ready adaptability of the files make it a technically superior method of photography in many ways. But the ‘warmth’ or ‘presence’ that is apparent in film owes everything to the analogue capture of light which we ‘analogue’ humans respond to viscerally. If success in business was compared to success in art we would find it hard to marry the ingredients necessary for either. There maybe some crossover but on the whole either standard requires different efforts. The debate over film versus digital follows the same logic… It’s very hard to fall in love with a number and art (because that is what we’re discussing here after all) is about love and its about seeing ourselves reflected in the medium – we messy, beautiful, unpredictable human beings. 



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