Most people don’t consider the factors involved in creating media content when they sit down to watch a movie or view a video on their smartphone. Their goal is to be entertained or informed. No matter the reason, many spend a lot of time doing it – adults in the United States spend an average of eight hours and 47 minutes per day watching screens. It doesn’t matter whether these screens are on tablets, smartphones, PCs, multimedia devices, video game consoles, DVDs, time-shifted television or live TV.
Sight is one of our five key senses. It enables us to consume information and filter it to develop our understanding of the world around us. Approximately 90 percent of information transmitted to the brain is visual, and visuals are processed 60,000x faster in the brain than text. Humans’ visible spectrum falls between ultraviolet and red light, and scientists estimate that most people can distinguish up to 10 million colors.
These factors, of course, affect our media viewing experience. With the advances in digital technology, media organizations are having to focus not just on what content to disseminate to consumers but also how to ensure it fits the way they watch it. For example, take into consideration these facts:
● The human visual system works hard to avoid misalignments. However, even if both eyes (or cameras) are perfectly aligned, vertical disparities between the retinal (or filmed) images can still occur.
● The eyes move partly to minimize retinal disparities; vergence eye movements work to ensure the lines of sight of the two eyes intersect at a desired point in space.
● It is customary to depict rapid motion smoothly to transmit from 25-30 complete pictures per second.
● Each picture is analyzed into 200,000 or more picture elements to provide detail sufficient to accommodate a wide range of subject matter.
● The successive illuminations of a picture screen should occur no fewer than 50 times per second, approximately twice the rate of picture repetition necessary for smooth reproduction of motion.
Breaking Down the Basics
According to research from Vanderbilt University, mental imagery directly impacts our visual perception and leads to a short-term memory trace that can bias future perception. So, what exactly is visual perception? The Interaction Design Foundation defines it as the process of absorbing what one sees, organizing it in the brain and making sense of it. A study at MIT found that the process can take only 13 milliseconds. It’s not the same as visual acuity, which is how clearly a person sees (i.e. 20/20 vision). Perhaps not surprisingly, basic visual perception can be influenced by cultural socialization.
The Brain Recovery Project promulgates that visual perception is made up of a variety of different parts. These include:
● Visual Closure: Knowing what an object is when seeing only part of it.
● Visual Discrimination: Using eyesight to compare features, like color and shape, from one to another object.
● Figure-Ground Discrimination: Differentiating a shape or word from its background.
● Visual Memory: Recalling something seen recently.
● Visual Sequencing: Distinguishing the order of numbers, letters, words or images.
● Visual Spatial Processing: Understanding how an object’s location relates to you.
● Visual Motor Processing: Using the eyes to coordinate body movements.
Unfortunately, there are challenges to visual perception for some people. These come in the form of visual stress and color vision deficiency often called color blindness. Present in an estimated 40 percent of poor readers and 20 percent of the general population, visual stress is a perceptual processing condition that can cause headaches and other problems. In fact, those prone to it may experience seizures when striped patterns (at approximately three cycles per degree) are shown at a flicker rate of about 20 hertz.
Color vision deficiency, which is experienced by an estimated eight percent of men and fewer than one percent of women, a deficiency in color vision. Red/green color blindness is the most common form.
SMPTE® – Education and Engagement
Our mission at the Society of Motion Picture and Television Engineers (SMPTE) is to drive the quality and evolution of motion pictures, television and professional media. We hope to provide relevant education to our global society of technologists, developers and creatives, along with setting industry standards and fostering an engaged membership community. By sharing information on topics like this, we aim to continue creating value for our members, partners and industry.