Leica KE-7A + Elcan 50mm f/2.0 [for US Military]
In 1972, Ernst Leitz Canada produced 460 pieces of KE-7A (M4 Schwz, black chrome) acquired by the US military, with contract numbers engraved on back of top cover. Usually the KE-7A come with a kit lens, Elcan 50mm f/2.0 with special C42-LS.39F hood.
KE-7As were fitted with modified shutters to operate in temperatures to -20 degrees Fahrenheit, were dust sealed for military field conditions and made to withstand explosive concussion (i.e. bomb blast).
Elcan 50mm f/2.0 lens was made in 1972 to fit the KE-7A. This very special lens uses infrared-absorbing glass made with lanthanum, a radioactive element that helps achieve an exceptionally high refractive index for heat control in making the optics. Elcan 50/2 only uses 4 lenses (called formula, 276), all air-spaced. My all time favorite lens designer , Walter Mandler was one of the Elcan 50 designer. The production model provides the first lens in lanthanum Crown glass Lak9, the second in Leitz glass, the third in dense Flint glass and the fourth in lanthanum Flint glass.