Glossary A
Glossary A
Aberration
Lens flaw that causes unsharp images, especially towards the edge of the lens field. These faults can be reduced by compound lens constructions, and the use of small apertures. There are six types of aberrations: spherical, coma, astigmatism, curvature of field, distortion and chromatic.
Abstract
Subjective, non-realistic image. An abstraction photograph generally contains a design of patterns or shapes where the identity of a subject is not evident.
Accessory shoe
Fitting to install accessories to a camera body; typically on top of the viewfinder, to attach a flash, a bubble level or any other accessory.
Achromatic
A lens system designed to reduce chromatic aberration, i.e. to render the same focal length for red and blue light wavelengths at the focal plane. Also, color having no chroma -- black, white and grays made by mixing black and white. All other colors employ chromatic pigments.