In every industry and every genre of life, there are specific terms that become the center of attention. As humans, we like to choose certain concepts to focus on, certain topics of interest to fixate upon. It helps to gain a feeling of understanding - when one masters the key concepts of an industry, they gain the ability to claim "expertise". The terms that describe these key concepts are called buzzwords, and they wield an immeasurable amount of power. Although intangible, the focus on buzzwords produces significant and impactful results.
The technology sector is one that has seen a wealth of hot topics come and go over the years. Some of these ideas transform into successful businesses, while others fizzle out into a quiet yet turbulent end. For the general consumer, the flurry of buzzwords can often seem confusing and overwhelming. While some have meaning and express a valuable potential, others deflate when probed too carefully. This article acts as a single part in a larger scheme, a new series focused on clarity and communication. Below is the third buzzword, debunked and explained, in an effort to provide a greater level of transparency into the tech world.
- Pixel
The word pixel came about from a mangling of the term "picture element", and it stuck. It's an individual programmable colour element, and the key to defining concepts such as resolution (that's up next). Thought of another way, a pixel is the smallest addressable unit of a digital image.
Pixels are defined on the software side of things, and don't refer to the actual color dots that make up the physical screen. If the screen resolution is changed to something below the maximum possible resolution, a pixel will be larger than an individual display cell on the screen. This, along with some clever rescaling techniques, is why you can play a 720p video on a 1080p screen, and vise versa. The colours are displayed via the RGB color scheme, combining red, green, and blue in varying amounts to create different hues.
PPI
The number of pixels per inch (PPI) has become a popular metric among review sites, specifically when talking about phones. Computer screens and TVs tend to be viewed from a distance, far enough away where our brains don't have any trouble reconciling small dots into discernible images. With phone screens so close to our eyes however, this can at times become an issue.
There's a concept that the human eye can't perceive much past 300 PPI. The idea became widespread with the introduction of the iPhone 4. In a press conference concerning the launch of the then-new Apple product, Steve Jobs popularized the myth as a marketing technique to emphasize the clarity of their 326 PPI screen. It is, however, exactly that: a myth.
The 300 PPI limit is based on the 1860's notion of 20/20 vision. Most people assume that 20/20 means you have perfect vision, the best vision possible. But this is wildly untrue, and is simply a metric of average vision. The inventor of the system, Doctor Herman Snellen, only ever intended for his vision acuity test to act as a measurement of "standard" vision, but it became blown out of proportion. It means you can read the Snellen chart from the standard of 20 feet away (6 meters), but your vision doesn't just drop off immediately thereafter. Many people can resolve images much further from this, with equal clarity. So if 20/20 is the limit of your vision, than Steve Jobs was right - 300 PPI is roughly the height of clarity, for you. With the commonality of vision correction however, the average person today can resolve far beyond 20/20, and research indicates true upper limits of 600 to possibly 1000 PPI. A more accurate way of measuring human resolution exists using arc minutes, but this can take entire papers or books in itself. Astronomer and writer Phil Plait wrote a shortened and concise version concerning the topic, which I encourage anyone with an interest to explore further.