Entertainment / Photography / Lens Hood
Lens Hood: Opaque tube, either cylindrical, square of funnel shaped, use to shield a lens from stray light outside the field of view.
Lens Shade: See lens hood.
Portrait Lens: Lenses produced specifically for portraiture. They usually have a long focal length and produce a slightly diffused image.
Petzval Lens: Early lens system developed by joseph petzval. It had a very wide aperture and was relatively free from aberration. Many modern lenses have developed from this simple three-element design.
Positive Lens: Simple lens that causes light rays from a subject to converge to a point.
Reflex Lens: Alternative term for mirror lens.
Single Lens Reflex (SLR): Stands for single lens reflex. It is a camera of 35mm or medium format in which a system of mirrors shows the user the image precisely as the lens renders it.
Normal Lens: A type of focal length that seems to most closely approximate the human eye's range of vision (in actuality the range of vision is narrower in a normal focal length lens, with less illusion . . . View Full Definition
Process Lens: Lens system designed specifically for high quality copying.
Negative Lens: Is a simple concave lens that causes rays of light to diverge away from the optical axis.