While many seemed to enjoy my recent post on the role of perceptual adaptation in “overshooting” reflected lights—it is also important to keep in mind that the same mechanisms can lead to significant “undershoots” in very light regions. As such, I would like to share some thoughts on adaption awareness and intentional under/over-shoots in regard to viewing distance, optimal definition, and communicative efficacy.
For anyone that has ever studied photography, you are probably already familiar with the “exposure triangle” which contains as components shutter speed (measured in fractions of a second), aperture (f-stops), and film speed (or ISO rating, which is the level of sensitivity of the sensor or film). “Cambridge in Color” offers a great analogy for understanding exposure: “Achieving the correct exposure is a lot like collecting rain in a bucket. While the rate of rainfall is uncontrollable, three factors remain under your control: the bucket’s width, the duration you leave it in the rain, and the quantity of rain you want to collect. You just need to ensure you don’t collect too little (“underexposed”), but that you also don’t collect too much (“overexposed”).” The key, however, is knowing which setting/trade-off to choose, since each component setting also influences other image properties. For example, aperture affects depth of field, shutter speed affects motion blur, and film speed affects image granularity.
Like the quest to find the optimum exposure triangle for photographers, particular aspects of observational representationalist drawing and painting efforts require adjustment that also carry both advantage and disadvantage. Let’s look at one of these problems, one related to “value undershoots”, and see how “our own settings” can significantly impact the work.
For example, an initial glance at this simple still life setup from about 5-7 feet away yields an percept (IMAGE A) that results in the very light shell on the right nearly devoid of any surface structure (very near “blown-out”). There is a very slight gradation from the shadow side up towards the light before disappearing into a sea of bright, glowing white. However, as I sit closer and fixate on the shell, my vision begins to adapt to the light level, and more surface values and variations become visible (IMAGE B).
Quickly, my mind beings to consider the following questions:
1. Do I try to maintain the bright, significant crescendo of white describing the shell that I experienced upon first glance? (This will result in a great punch of contrast which can often facilitate successful communication over a subject over longer distances. However, surface information in the lightest regions here will be sacrificed resulting in a potential information void when the work is examined at very intimate proximities.)
2. Should I substitute the perceived value range of a single object that arises from one perceptual adaptation for another? (This might seem like a common-sense compromise—however this can often lead to an overall diminishment of global contrast and skew some value relationships, thus resulting in a diminishment of communication distance and overall form.) (IMAGE C)
3. Do I try to shift everything to find an “exposure” that maintains observable relationships when viewing the whole but allows for evenly distributed/diminished form and/or surface information? (This is also a viable choice, however doing so may result in some non-linear comparisons that are very difficult to keep track of and will often carry the cost of information-loss somewhere along the lightness continuum.) (IMAGE D)
Now I have spent the better part of my career working on the right balance of value overshoots, undershoots, substitutions and alignments that would hopefully yield an effective visual communication, maintaining a desired level of definition over a particular range of viewing distances.
So, based on your own representationalist goals, how do you determine the right balance of these considerations for yourself?