F-number lengths. Therefore, reduced–depth-of-field effects will require smaller f-numbers when using small-format cameras than when using larger-format cameras. Image sharpness is related to f/number through two different optical effects: aberration, due to imperfect lens design, and diffraction which is due to the wave nature of light. The blur optimal f-stop varies with the lens design. For modern standard lenses having 6 or 7 elements, the sharpest image is often obtained around 5.6–8, while for older standard lenses having only 4 elements (Tessar formula) stopping to 11 will give the sharpest image. The larger number of elements in modern lenses allow the
Adler Standard 6 Adler Standard 6 The Adler Standard 6 was the most important newcomer at the Berlin Motor Show in October 1926. It was a substantial six cylinder “limousine” (saloon) built by the Frankfurt auto-maker, Adler. Other body styles were available from coach builders. The model continued to be produced until 1934. The Standard 6 shared its wheel base with the less expensive four cylinder Adler Favorit which appeared early in 1929. The Standard 6 was also in most respects the blueprint for the longer more powerful eight cylinder engined Adler Standard 8 which arrived in 1928. The basic architecture of the