Buchanan Studios Blog

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Posts Tagged ‘camera

Photographic Term of the Week: Depth of Field

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Depth of Field is the range of sharp focus within an image. Measured in distance from the focal plane, depth of field (of DOF) is affected by many factors. Key factors being…

1. Aperture (f/stop.)  The smaller the aperture (higher f/number) the greater the depth of field, or more in focus.
2. Focus Distance. The farther the primary focus distance, the greater the depth of field.
3. Focal length of lens. The shorter the lens (lower focal length) the greater the depth of field.

By manipulating these factors the photographer can adjust the depth of field to suit their needs.

Many lenses have a printed DOF scale on the lens barrel to aid the photographer in determining how deep the field of focus will be. It’s worth noting, however, that there is no agreed upon standard for what constitutes sharp focus. Therefore scales will differ from manufacturer to manufacturer. Further complicating matters is the fact that in today’s world of different digital sensors within the same platform of lens mounts, a DOF that may have been acceptable with one camera body, may not be on another higher resolution body. Nonetheless, the optical principals of DOF remain the same across all lenses.

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Written by stevebuchanan

March 2, 2012 at 12:23 pm

Photographic Term of the Week: Camera Raw

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Camera Raw, or RAW format is a digital storage format for images captured with digital cameras. RAW files have the advantage of containing all of the data captured by the camera, before any digital processing. RAW files are also sometimes referred to as digital negatives. (Adobe’s DNG format is a type of RAW file.) Most end uses of digital images are capable of displaying no more than 8bits of information per color, whereas most digital cameras can capture far more (10, 12 even 16 bits.) Capturing images in RAW format allows the photographer to manipulate the image in post production with less of a chance of technical flaws becoming apparent in the final image.  (IE, more manipulation of color, exposure, density etc – with less digital artifacts like noise and banding.) After post production on the RAW file is complete, the photographer can then convert to a more standard file format such as TIFF or JPEG.

Drawbacks to using RAW include…
Increased file size over JPG
Proprietary format from manufacturer to manufacturer
Specialized software often needed to read and process RAW files.

Written by stevebuchanan

February 24, 2012 at 9:59 am

Photographic Term of the Week: Chiaroscuro

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Chiaroscuro is an Italian term that literally means light-dark. It refers to the tonal contrasts that give a represented object shape and definition or greater dramatic representation.

See this wonderful example from the National Gallery in London

Written by stevebuchanan

January 27, 2012 at 10:57 am