Major thirds tuning tuning's simplicity and consistency are not shared by standard tuning, whose seventh-chord fingering is discussed at the end of this section. Each major-thirds tuning repeats its open-notes after every two strings, which results in two copies of the three open-strings' notes, each in a different octave. This repetition again simplifies the learning of chords and improvisation. This advantage is not shared by two popular regular-tunings, all-fourths and all-fifths tuning. Chord inversion is especially simple in major-thirds tuning. Chords are inverted simply by raising one or two notes three strings. The raised notes are played with the same finger as the
Four Thirds system Thirds cameras came to an end after the introduction of the mirrorless Micro Four Thirds format. Discontinued models include: The Four Thirds lens mount is specified to be a bayonet type with a flange focal distance of 38.67 mm. There are currently around three dozen lenses for the Four Thirds System standard. Before announcing that it would stop production of Four Thirds lenses in early 2017, Olympus produced about 20 lenses for the Four Thirds System under their "Zuiko Digital" brand. They are divided into three grades — Standard, High Grade and Super High Grade. High Grade lenses have faster