The history of lens grinding and mathematical design for engineered glass has led to ever sharper representations of a scene on the recording medium of the time, whether glass plates or electrically charged silicon sensors. And while amateurs, avid enthusiasts, and professionals seem to want ever sharper and even 3-dimensional photographs, it comes at a psychologial cost.
Because of the conflation of “see” with “know,” there is a feeling that the sharpest focus gives the best understanding of a subject. That may be true in documenting shades of reflected light, color tones, texture, and so on, but to interpret a subject in its surroundings, both its physical and its historical context, there are more important things than resolving power for a particular lens. Paradoxically, the pricier the lens and the higher the user’s expectation for sharp focus, the more likely it is for the photographer to be preoccupied with the subject’s surfaces that are expressed so crisply with the pricier lens. As a result of this sharp focus on the image itself, the larger meaning, purpose, or significance of the subject may be overlooked or obscured.
The opposite case, where focus is very poor, also leads to preoccupation with the image qualities rather than the subject being recorded. And so, it seems, the best photo for communicating a subject together with its context or wider meaning is a picture that is well focused, but not so sharp that the viewer becomes fascinated with the tangible, life-like quality of the thing.
After so many generations grown used to photographic illustrations, advertising, documenting and instructional guides, there are high expectations for text or audio to come with images, still or moving. In the current generation the scale of image making has mushroomed by the creation of digital pictures and the exchange wirelessly by phone and computer. And software manipulation of photos has become difficult to detect with one’s eye alone, unaided by forensic tools of digital scrutiny. But despite knowing of trickery, people today still seem to cling to the idea that “a photo never lies; it must be true, just as it appears on the surface.” So the old equivalency between “I see” and “I know” is stronger than ever.
As the focus becomes even sharper than before, perhaps the people of the future will only take that old equivalency and regard it impossible to think otherwise than the appearance of what one’s eyes seem to know. When that state of affairs comes to pass, then it will be time to recall what The Little Prince (Antoine de St. Exupery) learned in his story, that “only with the heart can one truly see.” In other words, the full meaning or significance of a subject is not found in the descriptive lines that capture its surface character, but rather between the lines where the true character resides. Thus there is a parallel between lenses that focus well, but not too well –on the one hand, and knowledge that is comprehensive with granular precision, but also leaves room for ways of knowing that are not restricted to surface characteristics: in both cases the excessive focus on external qualities paradoxically can produce an illusion of certainty of knowledge that will blind the person to possible deeper or wider significance.