Intelligence Quotient (abbreviated IQ) Tests are under increasing attack as a fundamentally flawed means of determining intelligence because they do not take into account the complex nature of the human intellect and its different components. I suspect that they will eventually be thought of in much the same way that we think of phrenology today. Image Quality (also abbreviated IQ) is an interesting parallel.
A recent foray into the digital photography universe brought home to me the importance that both the manufacturers and the users of digital cameras place on Image Quality (IQ). It is a recent enough term that there is no general definition, but it generally refers to technical characteristics of a picture such as sharpness, resolution, distortion, color depth, color accuracy, etc. That’s fine as far as it goes but, for me, the problem begins when the IQ of one picture is said to be “better” than the IQ of another picture.
A picture is by its general nature an abstraction – an image representing an object. When IQ is used as a measure of the success of the abstraction it is assumed that the more literal the representation the better. But that assumes a particular purpose of making the image in the first place.
In advertising the purpose of an image is typically to guide the viewer’s thoughts from the general to the particular. A viewer who could be a customer for an expensive watch is shown a particular watch. The angle of the photo may be dramatic, the lighting may be creative, the setting may be imaginative, but the image of the watch itself must be sharp and it must be a literal representation of a particular watch. Otherwise, how is the potential buyer to recognize it in the jeweler’s display?
In art the purpose of the image is often to guide the viewer’s thoughts from the particular to the general. If a photographer wanted to represent a sense of urgency in a scene they might include an open pocket watch on a table in the foreground. Since the watch is not the main focus (figuratively) of the scene it might be better if it was not in sharp focus (literally). The last thing the photographer wants is the viewer of a courtroom scene wondering if the Elgin watch was made in Elgin Illinois or after the factory moved to South Carolina.
Which of these two hypothetical images of a watch is “better”? I suspect that many photographers today would say that the IQ of the former is better and, by extension, that the former picture is “better” too. The picture above was taken by my father ca. 1940. I don’t know why he chose to bias the focus towards the curb in the lower right corner rather than the building in the background. He was a good enough photographer that I know it was deliberate. Perhaps he meant it to be a picture of a road under construction with the building to provide scale and context. I happen to think it’s a damned good picture.