Photography by Randy Hanna

In the previous entry about hyperfocal distance, I introduced several mathematical  relationships that make all of this work.  Simply put, using the hyperfocal distance (HFD) at any given aperture, will produce the greatest depth of field (*).  By looking at some examples across different sensors (full frame and 1.5 crop factor) you can get an ideal of just how beneficial this information can be and how you can use it to your advantage.

Let’s quickly contrast the impact of  a full frame vs a 1.5 crop factor sensor across two focus settings to see the relationship.  Using a Nikon D3, 14mm focal length, f4 aperture, and object focus distances of 5 and 15 feet will return a zone of focus of 2.6ft (near) to 66.2 ft (far) and 3-9ft (near) to infinity (far), respectively.

The same settings on a Nikon D300 will yield a zone of focus of 3ft to 13 ft and 5.25 to infinity for focus points of 5 and 15 ft respectively.  Comparing the closer focus points across the two sensors, the full frame sensor will generate a greater depth of field.

A practical use of the HFD is to determine where to set your focus point to achieve the maximum depth of field.  Photographing in the sand dunes of Namibia, I wanted as much DOF as possible.  Using the HFD tables, I determined that a 14mm lens set f8 with a focus point of 5ft would return a depth of field of 1.76 ft to infinity.  Armed with this data, I simply manually set the focus at 5 ft and fired away, never touching the focus again (as long as I did not change the focal length).

I have found that using HFD information on wide angle lenses returns more images that are in focus than before.  Having said this, HFD is not something I use all the time, so learn when to use it and it will make a difference.

In the next and final entry on HFD, I will explore the HFD tables in more detail and several iPOD applications that make all of this easy.

* New York School of Photography

Cheers, Happy Holidays and happy photo’ing

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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,

Happy photo’ing

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The Sands of Namibia

Nikon D300, 17-55 @ 17mm, ISO 200, f10 at 1/160 sec

Deep in the sand dunes of Namibia, I was presented with a rolling light show of highlights and shadows as the sun rose from my left.  With the camera having significantly less dynamic range than the human eye, it is always a challenge to record an image that depicts, as close as possible, the scene as it was seen by the eye.  As many of you know, I am a technical shooter.  Shooting in the deserts of Namibia was truly a personal and technical challenge for me which resulting in pushing my photography skills to a new level.  Amidst a sea of sand, I worked hard to incorporate an artistic approach in many of my images.  I found myself paying a great deal of attention to lines, shapes, highlights and shadows to tell the image story.  Thanks to JP Caponigro and Andy Biggs for pushing me into this artistic journey!

This image is a good example of the use of hyperfocal distance knowledge to achieve the desired zone of focus.    Using hyperfocal tables, I was able to determine that focusing on the sand, 10 ft in front of me, the hyperfocal distance would be 5.37 feet (using f10 and the D300 at 17mm), resulting in a near focus limit of 3.48 feet and a far focus limit of infinity.  After determining these values, I simply reset the focus to 5 feet and shot.  To make all of this easier, I now use an iPod for my hyperfocal distance calculations rather than lugging around 10 pages of tables.  Thank you Mr. Apple.

Cheers and happy photo’ing

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