Hyperfocal distance is a function of focal length, f-number, and the circle of confusion (or most correctly, the circle of least confusion). Simply put, using the hyperfocal distance setting at any given aperture will result in the greatest depth of field (New York Institute of Photography). At the heart of the hyperfocal equation is a value known as the circle of confusion (CoC). The CoC is, without a doubt, the most misunderstood and controversial variable among imaging experts. The basis for the CoC has invoked a debate that has been raging for some 70 plus years and will certainly continue into the future as the purists refine the resolving power of imaging devices. Boiled down to the most basic level, the CoC is the reciprocal of resolution and is directly related to the sensor size of the digital camera. The CoC describes the smallest image element that retains identifiable details. Obviously, this would vary based on the distance from the object in primary focus.
Although I will further explain and provide examples of how to use hyperfocal distance in the next update, if you have an iPod or an iPhone, you are in luck because there are two good applications to assist you. Rather than carrying around a number of tables, simply let Mr. Apple do the math for you. In coming postings, I will review the hyperfocal distance applications as well as demonstrate several applications of hyperfocal focusing and the benefits of such, so come on back for parts II and III. ‘Til then,