When I paint from a photograph it seems an obscure action. A photograph is an ephemeral image of something and the action of then spending hours focusing on that fleeting 100th of a second seems strange. However the process of painting to me feels rather like taking notes on a particular text. If I skim read an academic text, I absorb only a fraction of the content. However, if I re-evaluate, take notes and question the text then I absorb a larger amount of detail. This to me is the same as painting. Essentially when I paint from photographs it is a closely observed view of a very short time period, which the brain did not have time to fully, process.
This is why the act of painting live without the aid of a photograph is a very different process. Everything is in flux from the light to the water content in the food I am painting especially if the painting takes several weeks to complete. Painting live is a battle between changing elements, where as a photograph is fixed apart from my own feelings and mood which change on a regular basis. To truly understand an object you must paint live, as you will understand the object over a period of time and not just in a fraction of a second. However, photography does have its benefits, in that it can capture a split second and hold the information steady for the brain to process and capture in a personal way.
The photograph is the most perfect picture. It does not change; It is absolute and therefore autonomous, unconditional, devoid of style. Both in its way of informing, and in what it informs of, it is my source (Gerhard Richter p.31 The Daily practice of painting).