Photography News
The ABC of Photography – Diffuser
Any material that scatters the light as it passes through it, Softening the illumination and making shadows less distinct. Diffusers are commonly used with artificial light sources. On sunny days, clouds act as natural diffusers.
Sources: Pixabay, NASA,Wikipedia, Susan Wingfield Lamar High School
Diffraction
Scattering of light caused by deflection at the edges of an opaque object. Diffraction causes slight fuzziness in the image when the narrowest apertures are used.
Sources: Pixabay, NASA,Wikipedia, Susan Wingfield Lamar High School
Differential focusing
Controlling depth of field to ensure that one element in the picture is sharp, while others are as out of focus as possible.
Sources: Pixabay, NASA,Wikipedia, Susan Wingfield Lamar High School
Depth of field
A measure of how much of a picture is in focus, from the nearest point in the scene to the camera that looks sharp, to the furthermost point that looks sharp. Depth of field is dependent on the aperture used, the distance that the lens is focused at, and the focal length of the lens.
Depth of field preview
Device found on some digital SLRs that enables you to see the viewfinder image at the actual aperture you’ll be using for the exposure. This gives a visual indication as to how much depth of field there is, and which parts of the resulting picture will be sharp or blurred. This is necessary because the viewfinder normally only shows the image as it would appear if the widest aperture available was used.
Depth of field scale
A scale found on some lens barrels that can be used to work out the depth of field for particular apertures, and that can be used for manual focus adjustments to maximize or minimize the depth of field.
Depth program
A program exposure mode in which the aperture and shutter speed is set automatically in order to provide the maximum depth of field while maintaining a shutter speed that’s fast enough for hand-held photography. With some cameras, the different subject distances measured by the multipoint autofocus system is also taken into account, and the focus is adjusted to suit.
Sources: Pixabay, NASA, Wikipedia, Susan Wingfield Lamar High School
Dedicated flashgun
A type of flashgun that’s designed to provide direct one-way or two-way communication with the camera. The amount of dedication varies enormously depending on the flashgun and camera. Increased dedication tends to provide a more accurate flash metering, as well as making the flash system easier to use successfully.
Sources: Pixabay, NASA,Wikipedia, Susan Wingfield Lamar High School
Decisive moment
The split-second when all the elements of a photograph simultaneously come together. The decisive moment is associated with Cartier-Bresson, who described photography as “the simultaneous recognition, in a fraction of a second, of the significance of an event as well as of a precise organization of forms which give that event its proper expression.”
DC
This features on the range of Sigma lenses that are designed specifically for use with crop-factor SLRs, and which can’t be used with full-frame models.
Sources: Pixabay, NASA,Wikipedia, Susan Wingfield Lamar High School
Daguerre, Louis
Louis Daguerre (1787-1851) was an artist and inventor who devised one of the earliest photographic processes, the daguerreotype, announced in 1839. It was made by coating a silver-plated copper sheet with light-sensitive silver iodide and exposing it in a camera to create a positive image.
Sources: Pixabay, NASA,Wikipedia, Susan Wingfield Lamar High School
Darkroom
A light-tight room for processing and printing Traditional photographs. Negatives are loaded into the processing tank in complete darkness, while a red/orange safelight can be used at the printing stage.
Sources: Pixabay, NASA, Wikipedia, Susan Wingfield Lamar High School
DA
Stands for Digital Auto, which features on a range of Pentax lenses that (unlike some earlier ranges) don’t have a manual aperture ring. They have a ‘Quick Shift’ mechanism that enables you to override focus manually, even when the lens is set to autofocus.
DA*
The premium lens range from Pentax, which Combines weatherproofing with the advantages of the DA range.
Sources: Pixabay, NASA,Wikipedia, Susan Wingfield Lamar High School