Spherical aberration - is the term for an optical fault caused by the spherical form of a lense that produces different focus points along the axis for central and marginal rays.
Curvature of field - optical defect that causes points on an object plane perpendicular to the lens axis to focus on a curved surface rather than a plane.
Astigmatism - aberration in which rays of light from a single point of an object (which is not on the axis of a lense) fail to meet in a single focus thus causing the image of a point to be drawn out into two sharp lines, one radial to the optical axis and another perpendicular to this line, in two different planes near the curvature of field.
Coma - optical defect that causes the image of an off-axis point of light to appear as a comet-shaped blur of light.
Distortion - an rectangle may appear as a barrel or pin cushion-shaped object.
Chromatic aberration - aberration caused by light rays of different wavelengths coming to focus at different distances from the lense.
Aspherical lens - a lens whose curved surface does not conform to the shape of a sphere; because a spherical surface lens has difficulty in correcting distortion in ultra-wideangle lenses or coma in large-aperture lenses brought about by spherical aberration, an aspherical lens is used.
Aspect Ratio - the ratio of width to height in photographic prints - 2:3 in 35 mm pictures to produce photographs most commonly measuring 3.5 x 5 inches or 4 x 6 inches.
more to come….
Tags: photo, photography, glossary, terms
My Name is Lau, I'm 23 and I'm from Cluj-Napoca, Romania. Nature Photography is my passion, and secondary, Abstract Photography, but other kind of photographic challenges please me as well.
