In the reports, one clinician noted no differences that were not negligible. The Propaganda for Reform in Proprietary Medicines, Vol. 1 of 2 Various The entire subject of adenomyoma is dealt with from the standpoint of the pathologist, the clinician, and the surgeon.
focal point - a point of convergence of light (or other radiation) or a point from which it diverges. focus. point - the precise location of something; a spatially limited location; she walked to a point where she could survey the whole street.
The focal point is denoted by the letter F on the diagrams below. Note that each lens has two focal points-one on each side of the lens. Unlike mirrors, lenses can allow light to pass through either face, depending on where the incident rays are coming from. Subsequently, every lens has two possible focal points. The distance from the mirror to the focal point is known as the focal length (abbreviated by f). Technically, a lens does not have a center of curvature (at least not one that has any importance to our discussion). However a lens does have an imaginary point that we refer to as the 2F point. This is the point on the principal axis that is twice as far from the vertical axis as the focal point is.