Version One: The original 28mm f2.8 Elmarit (9/6) was introduced in 1965 (circa 1965-72 serial numbers 2,060,000 to 2,31X,XXX)) to replace the aging 28mm f5.6 Summaron which was a fine and sharp symmetrical double Gaussian derivative but of too limited aperture to be competitive for its time. Version One is an optically highly complex intricate difficult to execute design; and hence was very expensive. It is prized by collectors for rarity but is relatively undistinguished optically when compared to later offerings. Filter: Series VII early, E48 later.

Version Two: Introduced in 1972 (circa 1972-79 serial numbers 2,314,801 - 2,978,550) the design of this (8/6) lens is an example of how a less than inspired mechanical camera construction can have a detrimental impact on fundamental lens design parameters. The lens is a retrofocus design to accommodate the physical design of the M5...not LEICA's very best thinking historically ! Leitz/Leica, ignoring an opportunity to advance wide angle optical technology and its reputation succumbed to the artificial design constraints inherent in a faultily conceived M5 and quoting Erwin Puts: "...The Midland design equals but does not surpass the previous symmetrical design...The M-28 (II) is of lower contrast in the outer zones and even stopped down to 1:8 renders fine detail with fuzzy edges..." Filter: Series VII early, E48 later.

Version Three: This second Midland Canada design (8/6) is much improved over the similar 1972 version and according to Erwin Puts "...set the standard for the 28mm focal length for years to come...." Filter E49

Version Four (final version not employing aspherical surfaces): Introduced in 1992 (circa 1992- Serial number range 2,977,551- ) and designed (8/7) in Solms Germany after the move from Leitz Wetzlar. This design achieved the combined objectives of being smaller, lighter and the sharpest formulation 28mm to date. Filter E46.