The fundamental difference between a digital camera and a traditional one lies in the type of medium on which the images will be recorded. Instead of the old emulsion made of photosensitive silver halides for black & white and dyes in the case of color, there is now an electronic component, the sensor, which has the task of converting the light rays received through the lens into electrical charges.
The obtained analog signals are then sent to other electronic circuits that amplify them and convert them into digital data.
Without delving into the complex world of digital technology, we will try to understand what this difference actually leads to, but to do so it is useful to recall the characteristics of photographic film that lead to choosing one emulsion over another.
The analog films can be black and white and color, negative or reversal, for daylight, tungsten, and infrared light. Each of these has peculiar characteristics: sensitivity, exposure latitude, grain quality, contrast, ability to reproduce the finest details, color rendering, and color fidelity. All these elements contribute to the final image quality and achieving the desired effect.
Thus that professional photographer who still uses traditional film today can choose the type of film according to the work to be done, while the amateur can decide which film to rely on with almost mathematical certainty of the final result.
From a purely photographic point of view, the advent of electronic sensors has not changed much because modern digital cameras must necessarily offer characteristics similar to traditional ones. However, the terms and ways of working have radically changed.
The grain has disappeared but there is “background noise.” The low sensitivity that characterized high-resolution films like Fuji Velvia 50 or Kodachrome 64 no longer exists because digital starts from minimum sensitivities of 200 ISO with surprising results. If you are lucky enough to shoot with a professional digital SLR, then even at 6400 ISO you will get an absolutely marketable product.
The exposure latitude, that is, the film’s ability to record as much information as possible in the highlights and shadows and its tolerance to overexposure and underexposure, is very reduced in the electronic sensor because it records a narrower data range. Fortunately, sophisticated software techniques, such as HDR, brilliantly solve the problem. Color rendering and color fidelity are largely guaranteed by the quality of optics now specifically designed for digital, but even in this case, photo editing programs can transform awful photographs into real works of art.
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