Landscape, Nature And Travel Photography

One interesting aspect of the natural world that can wreak havoc with our ability to capture a sharp image is the phenomenon of atmospheric distortion. Atmospheric distortion is particularly troublesome for photographers using longer lenses or telescopes. Temperature variations in the air, whether at ground level or in the upper reaches of our atmosphere, will refract light creating a blurred appearance to our eye. While this fluctuation of light may look cool on video it is a still photo killer.

The physics of this phenomenon is quite straight forward.

1. Warm air rises and cool air sinks.
2. Light travels faster in warmer less dense air versus cooler denser air resulting in the refraction of light.
   Note: This is the exact same phenomenon behind seeing mirages.

Transamerica Pyramid & Berkeley Hills

Canon 1Ds Mark III at 1600mm (800mm + 2x extender)

To exemplify this effect there are 3 photos in this post. The original (above) was taken with an 800mm lens I rented from BorrowLenses.com. The following two photos are 1:1 crops of the original to highlight the impact atmospheric distortion can have at different distances.

Atmospheric Distortion Example - Foreground of "Transamerica Pyramid & Berkeley Hills" photo

Canon 1Ds Mark III at 1600mm (800mm + 2x extender) subject is 4.6 miles away.

As you can see the density fluctuations in the air resulting from the rising warm air and sinking cool air refracts light in such a fashion it is impossible to attain a sharp image. The Transamerica Pyramid building (above) was approximately 4.6 miles away in this photo, while the home in the Berkeley Hills in the background of this image was approximately 14.25 miles away. The extra 10 miles of air amplified the refraction of light a bit more and appears even softer when combined with the an image that isn’t employing maximum depth of field. In each of these instances the geometry and straight lines of the architecture highlight the impact this type of distortion can have on a photo subject.

Atmospheric Distortion Example - Background of "Transamerica Pyramid & Berkeley Hills" photo

Canon 1Ds Mark III at 1600mm (800mm + 2x extender) subject is 14.25 miles away.

The takeaway from this particular example is that if you’re photographing a landscape, nature, wildlife or astrophotography subject be sure you’re aware of factors that can result in atmospheric distortion (weather conditions, time of day you’re shooting, etc.) Alternately if you’re shooting with a camera that also can capture video, experiment filming this phenomenon. Seeing the light fluctuate in video is always better than seeing a blurry still photo.

Technorati Tags: photo, photography, terminology, atmospheric distortion, San Francisco, California, travel, Transamerica Pyramid

One of the greatest challenges facing photographers is dealing with the limitations of film or digital cameras in regard to Dynamic Range.  Over the years photographers have been and continue to be very creative in managing the limited range of light in which film or digital sensors can capture. In an effort to best reproduce what our eyes/brain see, photographers have developed techniques that balance the exposure of scenes with light ranges too great for film or digital sensors to handle.  Two techniques most often used to do this include the use of Graduated Neutral Density filters and now HDR image processing.

The differences between these two techniques are critical to distinguish in that one, GND filters, are for all intents and purposes a pre-processing technique, while HDR is a post-processing technique. GND filters enable photographers to manually adjust how much light from bright portions of a scene reaches ones film/sensor when the photo is taken. HDR on the other hand is the blending of multiple exposures on a computer to create a single image with a dynamic range that depending on the settings can look similar to what the human eye/brain might see. While both of these techiques can work well they do generate different looks.

Graduated Neutral Density filters in essence are plastic or glass filters with a graduated neutral gray color coating. The transition between the graduated gray to the clear portion of the filter can either be “hard” or “soft”. Hard GND filters have a more defined and abrupt transition while Soft GND filters have a broader and more gradual transition. As to which type you should use depends on the scene you photograph. Some scenes will have a well defined horizon line such as an ocean sunset photo in which a hard GND filter will work well, while a lake sunrise photo with a treeline may require the more gradual transition provided with a soft GND filter. Using the right GND filter type will make the filters use transparent to the viewer of your photograph.

Hard and Soft Graduated Neutral Density Filters

Photo courtesy of Ron Niebrugge

An example of a scene captured with and without a Soft 3-Stop Graduated Neutral Density filter. Note the detail in the sky that is recovered with the use of the filter.

With the use of a Graduated Neutral Density filter

Without the use of a Graduated Neutral Density filter

Other write ups on this subject:

Graduated Neutral Density Filters – Niebrugge Images

Graduated Neutral Density Filters – Wikipedia

Technorati Tags: photo, photography, terminology, Graduated Neutral Density, filter

One of the most essential pieces of knowledge to understand in order to attain sharp images, particularly for landscapes, is the principle of hyperfocal distance.

Phil Davis put it best in Photography, 1972

“When the lens is focused on the hyperfocal distance, the depth of field extends from half the hyperfocal distance to infinity.”

The general tip to burn into your memory is focus 1/3 of the way into your photo with a smaller aperture setting to maximize your depth of field.

image courtesy of DOFMaster

A great online resources to reference when researching hyperfocal distance for your gear is DOFMaster’s Depth of Field Calculator. In addition Vividlight Photography also has a great article on this subject What is Hyperfocal Distance and Why Should I Care? were they provide an Excel or PDF Hyperfocal Distance Chart that can be put in your camera bag.

View more photos of the Arctic National Wildlife Refuge (ANWR)

Technorati Tags: photo, term, terminology, Hyperfocal Distance, Arctic National Wildlife Refuge,   Arctic Refuge,   ANWR,   landscape,   photo,   photography,   Alaska,   wildflower, stock photo