fWert

fWert is a term used in different fields, and its meaning depends on the context. In particular, it may refer to concepts in photography (the f-number) or in statistics (the F-statistic).

In photography and optics, the fWert (f-number or f-stop) describes the ratio of a lens’s focal length to the diameter of the entrance pupil, defined as f-number = f/D. It governs image brightness and depth of field. A smaller fWert, such as f/2.8, yields more light and a shallower depth of field, while a larger fWert, such as f/16, yields less light and greater depth of field. Exposure is inversely related to the square of the f-number, and the f-number interacts with shutter speed and ISO in exposure calculations.

In statistics, the F-Wert (F-statistic) is used in analysis of variance (ANOVA) and regression to test hypotheses about group means or model components. It is the ratio of the mean square between groups to the mean square within groups: F = MS_between / MS_within. A large F indicates that observed differences among group means are unlikely under the null hypothesis. The F-statistic has associated degrees of freedom for both the numerator and denominator, and the p-value is obtained from the F-distribution.

In practice, fWert is most commonly encountered in photography as the f-number; in statistical reporting, it appears as the F-value. See also f-number and F-statistic for related concepts.