Since the arrival of digital photography on the market analog (analogue in European usage) has come to refer to any other photography, i.e. photography using film (or previously, glass plates).
Strictly, this is a misuse: 'analog' is from the Greek analogos, 'proportionate'; One thing may be said to be an analog of another if it behaves in a significantly similar way. In electronics and industry, analog systems are those where measurement and control are done using voltages or currents which vary continuously in response to the variation of real flows, temperatures etc. Clocks which display the time with hands on a traditional circular dial may be called analog clocks. However, a silver emulsion does not really behave in an analog way. The word has come to be applied to film-based photography simply by back-construction after the invention of digital cameras.
It should be noted that most TV/video cameras were, until recently, analog electronic devices. The few still-video cameras (like the original Sony Mavica) made shortly before digital cameras are perhaps truly analog devices.
The French use a more descriptive term for film photography: la photographie argentique - silver photography, and 'silver-process photography' is used in English, though not widely.
- Concise Oxford Dictionary, ninth edition. Oxford University Press, 1995, p44.