Micro Four Thirds system functions.) For the Four Third lenses that can be mounted on MFT bodies, see Four Thirds system lenses. For the Four Third lenses that support AF, see the Olympus website. For those that support fast AF (Imager AF), see the Olympus website. Wide zoom lenses Standard zoom lenses Telephoto zoom lenses Superzoom lenses On Jan 9, 2012 Sigma announced its first two lenses for Micro Four Thirds, the "30mm 2.8 EX DN and the 19mm 2.8 EX DN lenses in Micro Four Thirds mounts". In a press release posted on January 26, 2012, Olympus and Panasonic jointly announced that "ASTRODESIGN,
Ladder of thirds Ladder of thirds A ladder of thirds (coined by van der Merwe 1989, adapted from Curt Sachs) is similar to the circle of fifths, though a ladder of thirds differs in being composed of thirds, major or minor, and may or may not circle back to its starting note and thus may or may not be an interval cycle. Triadic chords may be considered as part of a ladder of thirds. It is a modal frame found in Blues and British folk music. Though a pentatonic type, the melodies come "into being through piling up thirds below and/or above a