Every serious hobby or profession has acronyms and terms that leave the uninitiated scratching their heads in wonder. Thus, it seems to make sense to start a glossary of terms that I can update as I go along.
D
Das Wesentliche - a German word that refers to the "essence" of something. In the world of Leica, it means only what is needed, the essence of taking a photograph. That is why a Leica M typically has simple controls: focus, aperture, shutter speeds, and ISO settings (for digital cameras).
E
Erwin Puts - A writer who has published a variety of books on photography and Leica cameras, lenses, and history. Some writing is extremely technical, but his works are part of libraries for serious study of Leica. Erwin’s website has a wealth of information.
EV1 - The Leica M EV1, or as I am fond of saying, the Leica M11 EV1, with an EVF instead of an optical rangefinder. The Leica Camera AG product page for the EV1.
EVF - Electronic Viewfinder; this is the color LCD that we see when we look in the small viewfinder on the top right. Some older SLRs look through the lens in the viewfinder. An EVF looks through the sensor, which is why it is like a tiny computer monitor showing what the sensor sees.
L
Leica Society International (LSI) - A world-wide society focused on everything Leica with special relationships in the Leica Camera A.G. community. An incredible organization I have been involved with for 20 years and worth every penny of joining. Read about it here.
M
MTF or MTF Graph - the Modulation Transfer Function. This is a pretty technical term, but it refers to the % contrast of light moving out from the center of the lens to the edges, and it is based on the frequency of light. Frequency for an MTF graph is measured in line pairs per millimeter (lpmm). It uses line pairs because one is white and one is black. Contrast is measured by how clear the edges are of the black and white line pairs. Leica typically produces graphs for 5, 10, 20 and 40 lpmm. Erwin Puts refers to these as coarse detail (5), fine detail (10), very-fine detail (20) and extremely fine detail (40).
N
Nocitlux - A Leica term that refers to a lens with a maximum aperture of more than f/1.4. Some examples include f/0.95, f/1.0, and f/1.2 and f/1.5.
S
Summicron - A Leica term that refers to a lens with a maximum aperture of f/2.0.
Summilux - A Leica term that refers to a lens with a maximum aperture of f/1.4.