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

The terms “magic hour” and “golden hour” are often used interchangeably, both describing the same lighting phenomenon. The “golden hour” is the hour after sunrise and before sunset when the light is less intense and fittingly golden. At this time sunlight shines through the earths atmosphere at a more acute angle resulting in wavelengths of light, other than red, being scattered at a greater frequency. The net result is redder more golden light making its way to the Earth’s surface. Additionally the acute angle that sunlight falls at this time creates dramatic long shadows for higher contrast imagery and highlights are less intensely lit compared to other times of day.

The “golden hour” is coveted by photographers as the warm light enhances a variety of subjects from landscapes to portraits to cityscapes.

Curious about the impact of smoke, pollution and/or clouds on the “golden hour”? Then I recommend reading The Colors Of Twilight And Sunset by Stephen F.Corfidi

An example of “golden hour” light falling on the Marin foothills in California.

More of the Photo Term Series

Technorati Tags: photo, term, terminology, golden hour, magic hour, sunset, sunrise, California, landscape, Marin, foothill

Dynamic range, in relation to photography, most commonly describes the light sensitivity range of a photographic medium whether slide/print film or a digital sensor.

Unlike other definitions of Dynamic Range I think it’s important to discuss the relationship of the human eye and brain and what we determine as the standard of dynamic range. The eye is in all intents and purposes a sensor that can detect texture, shape and color with great sensitivity. Our brain, with years of learned understanding of how the world works and is constructed, quickly layers information together from detected light ranges to create an image of what is before us. As a result with out thinking we see the world with a high level of fidelity and detect detail from dark shadows to bright highlights.

Photographers often become frustrated because the tools at our disposal lack the ability to recreate the full range of light we inherently see. For film and digital alike, photographers think in terms of stops of light (referring to f/stop). It’s widely accepted that film has a dynamic range of 4-8 stops, digital sensors have a theoretical dynamic range of 10-14 stops and the human eye a dynamic range of 20-24 stops*.
Note: *The fixed dynamic range of our retina is about 6 stops, but exposure is variably adjusted chemically and by our iris as it contracts and expands.

Due to the disparate range of light detected between these mediums and our eye, photographic images and even prints have a perceivable difference in appearance compared to the true scene we see with our naked eye. Photographers using their artistic license have used the limited dynamic range of film or digital sensors to create different effects whether silhouettes or High Dynamic Range Imaging.

Dynamic Range in Digital Photography by Sean McHugh

Dynamic Range of the Human Eye – Wikipedia

The Eye and the Camera – Luminous Landscape

Example:
Note that for this slide film exposure of Half Dome below, the dynamic range of light and resulting detail isn’t equivalent to what you might see with your naked eye. Detail is challenging to see in both the highlights of the snow and the shadows of the trees and valley wall.

Technorati Tags: dynamic range, photography, terminology, light, sensitivity, human, eye, digital, sensor, film

 ”In photography and optics, vignetting is a reduction in image brightness in the image periphery compared to the image center.

Although vignetting is normally unintended and undesired, it is sometimes purposely introduced for creative effect, such as to draw attention to the center of the frame. A photographer may deliberately choose a lens which is known to produce vignetting. It can also be produced with the use of special filters or post-processing procedures.” – Wikipedia

Example:

Vignetted version (note the darkened corners)

Non-vignetted version (lighter corners)

Technorati Tags: vignetting, photography, photo, terminology, term, Glacier National Park, Montana, landscape

“Barrel Distortion, in which image magnification decreases with increasing distance from the optical axis. The apparent effect is that of an image which has been mapped around a sphere. Fisheye lenses, which take hemispherical views, produce this type of distortion as a result of a hemispherical scene being projected onto a flat surface.” – Wikipedia

Or…

“Barrel distortion is a lens effect which causes images to be spherised or “inflated”. Barrel distortion is associated with wide angle lenses and typically occurs at the wide end of a zoom lens. The use of converters often amplifies the effect. It is most visible in images with perfectly straight lines, especially when they are close to the edge of the image frame.” – DPReview.com

Examples:

16mm end of a 16-35mm lens on a full frame film SLR

Technorati Tags: barrel distortion, photography, photo, terminology, term, Golden Gate Bridge, California, San Francisco

The telephoto effect, created aptly when using longer focal length lenses, creates an altered perspective where distances are compressed or shortened. The net effect makes objects, that may be quite some distance apart, look close together. The longer the focal length the more pronounced this effect.

An example of this can be seen in my photograph “San Francisco” where the Golden Gate Bridge and city skyline are actually miles from each other.

Technorati Tags: telephoto effect, telephoto, long lens, photo, term, terminology, education