Experiments with Digital Noise

Using title1-a

Photographing scenes where the light is very low can produce digital noise levels that can result in pixels which include more noise data than real photo light data. In digital photographs, these pixels usually appear as random dots, speckles or stains. In addition, the image quality may be compromised by the resulting image artifacts, loss of sharpness or color degradation. We refer to these random dots, white speckles, visible streaks, color stains and degradations as digital noise.

From a technical point of view, digital noise is the visual manifestation of a lower signal-to-noise ratio. Similar in appearance to film grain, digital noise can result in visible artifacts in an image and is comparable to the background hiss experienced in audio systems. [1] Noise increases with higher ISO setting in the camera, with the length of the exposure, the color temperature, and different camera sensors and lenses. [2] At increased ISO settings, the sensor becomes more sensitive not only to the light levels, but to random signals from other sources. [3] Digital noise is less pronounced in the brighter areas of an image as the signal is stronger in these areas of the image. Long exposures can accentuate unwanted noise as well as shooting in heavy shadow and low light conditions. The sensor size and the pixel density greatly influence the noise levels of an image. In some situations, you will find that it is impossible to completely prevent digital noise.

 Digital Noise at 400percent 

Detail enlarged to 400% showing distinctive luminance noise: Altar Crucifix, Mission La Purisima Concepcion.

Digital noise has two elements:  chrominance and luminance. Chrominance or color noise appears as splotches of random green, magenta and blue dots whereas luminance noise is colorless and references the variations of lightness in an image. Similar to film grain, luminance noise may add textural details to an image. [4] Although digital noise often detracts from the aesthetics of a photograph, acceptable and unacceptable levels of noise is a subjective decision. In some cases, digital noise may be considered a desirable effect, and in those cases, digital noise may contribute positively to the overall aesthetics of an image.

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The vintage Asahi Takumar F/3.5-55mm Lens attached to a full frame Sony A-900 DSLR using a lens adapter.[5]

Recently when photographing in the low light of the chapel at Mission La Purísima Concepción near Lompoc, California, I noticed the pleasing effects of digital noise produced at high ISO settings while using an Asahi Takumar F/3.5-55mm lens originally manufactured for the Pentax 6×7 medium format film camera. Intrigued by my initial results, I continued to experiment with the Asahi Takumar F/3.5-55mm lens in photographs of mission statuary at Mission San Miguel Arcángel in San Miquel, California. With each example, the Asahi Takumar F/3.5-55mm lens was attached to a Sony A-900 DSLR using a lens adapter. In the available subdued light of the missions interiors, the lens was opened to the largest aperture of F/3.5 with an ISO setting of 6400, a combination of exposure factors which appeared to minimized the less pleasing chromatic noise and accentuate the luminance noise. The photographs created with the massive lens produced exceptionally smooth gradations in the bokeh or the out of focus areas of the photograph.  In these examples, I approached digital noise as an opportunity for experimentation and used digital noise in a counter intuitive manner to purposefully integrate digital noise into the aesthetics of the images. By testing the limits of our digital tools, experiments with digital noise challenges “the illusion of control” and  suggest that our “digital tools to be only as perfect, precise, and efficient as the humans who build them.” [6]

With each photograph of mission statuary, the lenses, high ISO setting, sensor, and subdued lighting produced an aesthetic which I felt appropriate to the objects. Beauty is a concept of perception, [7] and the accentuated patterns and textural detail in the digital noise present in my photographs references the dusty, unknowable presences of the haunting and beautiful 17th century statuary. These experiments with digital noise point to the limits of photographic representation and acknowledges as well, the limits of our ability to know the past shared by the objects of worship placed before my lens. Beauty is often associated with light and radiance and supports the notion of beauty as illumination.[8] Within the imperfect recording of illumination resides the aesthetic strength of digital noise, and is the source of its beauty.

Altar Crucifix, Mission La Purisima Concepcion, Lompoc California

Altar Crucifix, Mission La Purisima Concepcion, Lompoc, California

Statue of St. Aquinas, Mission San Miguel Archangel, San Miquel, California

Statue of St. Aquinas, Mission San Miguel Archangel, San Miguel, California

San Miguel Archangel Conquering the Devil, Mission San Miquel, California

 San Miguel Archangel Conquering the Devil, Mission San Miguel, California

 

David Arnold, February, 2015.

 

Citations/Notes:
[1] Digital Camera Noise Part 1, Cambridge in Color
[2]Emil Martiec, Noise, Dynamic Range and Bit Depth in Digital SLRs. 
[3] The term ISO refers to the film or digital sensor’s sensitivity to light. The higher the ISO setting the greater the film or sensor’s sensitivity to light.
[4] Digital Camera Noise Part II, Cambridge in Color.
[5] The Asahi Takumar F/3.5-55mm Lens was manufactured in the 1960’s as a wide-angle lens for Ashai Pentax 6X7 medium format camera. The lens is highly regarded for his sharpness and is unique for its massive size. The lens has a filter size of 100mm. Used on the Pentax 6×7, the lens is the equivalent to a 28mm lens on a 35mm camera, and when used with an adapter for a full frame DSLR, the lens is a 55mm lens.
[6] Kim Cascone, The Aesthetics of Failure: “Post-Digital” Tendencies in Contemporary Computer Music”, Computer Music Journal 24:4 Winter 2002 (MIT Press).
[7] Crispin Sartwell, Six Names of Beauty, p. 10.
[8] Umberto Eco, History of Beauty, p. 37.

 

Downieville Cemetery: Portraits of Gravestones

The Downieville Cemetery

Situated at the bottom of a deep narrow canyon at the confluence of the Downie and Yuba Rivers, Downieville, California prospered from the gold taken from the fast moving alpine rivers and streams. At the peak of the Gold Rush, about 5,000 miners worked extensive hydraulic diggings and deep rock mines in the area. Then, Downieville was one of the largest city in California.  Today, about 300 permanent residents enjoy the isolation and beauty of the canyon.[1]

On a steep slope on the north side of the Downie River canyon and about a mile up river from the confluence with the Downie and Yuba Rivers sits the Downieville Cemetery. Founded in the 1876, the Downieville Cemetery followed trends established by the rural cemetery movement begun in the early nineteenth century. Sometimes referred to as the Masonic Graveyard or Pioneer Cemetery,[2] Downieville’s cemetery consolidated graves from two small cemeteries begun near the town center. Like nineteenth-century rural cemeteries, the Downieville cemetery merges styles drawn from a multiplicity of landscape garden motifs: obelisks, miniature columned gates, urns, Gothic inspired wrought iron grave enclosures, angels atop tall monuments, cherubs, and holding hands craved into gravestone reflect the shifting nineteenth-century views on death and the remembrances of the dead.

The rural cemetery served the expanding nineteenth century urban culture as a place of moral improvement and social reform and suggested that death was a presence, a long sleep, and that the graves set in a natural setting would be eternal homes. As nature sanctuary, the nineteenth century rural cemetery is place of memory and beauty, with an emphasis not on death, but on art, hope and transcendence.[3] The American rural cemeteries were founded on the needs for healthy burial grounds placed away from the expanding population centers and on the Romantic movements connections to nature. Based on English landscape garden plans, rural cemeteries were designed as the first public parks and expressed a nostalgia for death culled from classical authors such as Virgil [4] :

“Then we are sent to spacious Elysium, a few of us to possess the blissful fields. All these that you see, when they have rolled time’s wheel through a thousand years, the god summons in vast throng to Lethe’s river, so that, their memories effaced, they may once more revisit the vault above and conceive the desire of return to the body.” [5].

Downieville’s historic cemetery exemplifies the picturesque tradition of the nineteenth-century rural cemetery: a ramshackle gate opens onto a place of quiet contemplation and meandering steps and paths lead in no particular direction,  and unkempt bushes, vines and tall grasses spread over grave enclosures. Dead branches and trees co-exist alongside new growth, to suggest that death is a natural cycle, and even when the river is low, and like Virgil’s Elysium, the sounds of rushing water filter over the picturesque landscape of death.[6]

Portraits of Gravestones

I arrived at the Downieville Cemetery just as the sun dropped into the top branches of the pine trees at the ridge line. At first disappointed that I had missed the light, I began to wander up the steep hillside over the terraced cemetery grounds. About halfway up the hill, I began to notice a diffused light bathing the gravestones in a soft and even glow. As I began to photograph the gravestones and enclosures in earnest I became fascinated by the uneven placement of the gravestones on the terrance slope. Some of the grave monuments stood tall, while others leaned forward and back creating diagonal and overlapping lines and shapes in the viewfinder.  The steep slope of the hill accentuated size distortions generated by the reduced angle of view offered by portrait lens which I selected for this series.

The overlapping of weeds, grasses, gravestones and monuments continue the picturesque intentions of the rural cemetery movement. The soft bokeh generated by the portrait lens speaks the nineteenth century sentimentality of mourning. Nineteenth century gravestones stood as markers for the departed and photographs I created are intended as portraits of those gravestones and monuments left in remembrance of the departed.

 

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Mounting the Fujian China TV GDS 35mm F1.7 lens to the Micro Four Thirds Lumix G with an adapter.

 

The Fujian China TV GDS 35mm F1.7 lens

For the Downieville Cemetery series, I used Fujian China TV GDS 35mm F1.7 lens purchased new from Amazon for $22, and a simple screw mounted lenses adapter was an additional $9. The Fujian China TV GDS 35mm F1.7 lens is surprising sharp at the focal point, with a soft bokeh falling off from the center of the image. The 35mm F1/7 mounted to the Lumix G Micro Four Thirds camera is the equivalent of a short telephoto or portrait lens on a 35mm format film or full frame sensor camera. The introduction of the Micro Four Thirds camera systems has opened new fields of experimentation with inexpensive manual focus lenses. With a thinner camera body achieved by the elimination of an internal camera mirror, the Micro Four Thirds lens mount has a flange focal distance of 20mm, a very shallow distance which permits the use of a wide range of lenses from manual focus 35mm to C-mount lens. The C-mount standard, first introduced by Kodak in 1923, were engineered for 16mm film and 8mm film cameras. In the 1950’s, television and early video cameras employed the C-mount standard.[7] C-mount lens are surprising inexpensive. I was very happy with how the Fujian 35mm F1.7 lens imaging characteristics supports the formal, conceptual and aesthetic choices expressed with the Downieville Cemetery series.
©David Arnold, 2013.
Works Cited
[1] Douglas E. Kyle, Historic Spots in California, p. 475-6.
[4] Margaretta J. Darnall, “The American Cemetery as Picturesque Landscape: Bellefontaine Cemetery, St. Louis,” Winterthur Portfolio, Vol. 18, No. 4 (Winter, 1983), pp. 249-269