Noctilux – F0.95 ~ F1 – For those nocturnal tendencies within us all Leica gives us the NOCTILUX. The legendary lens that will bring light to your photo when you have no light available. Open it up to F1 and get ready for some fun. The new 0.95 version is scary sharp wide open and had that 3D look in spades. Still, the old F1 version has a little more of that classical magic. These are unique lenses and in some cases they can render in a painterly way. 

Noctilux – F1.2 Aspherical 50mm is the first aspherical mass-produced lens in the world in 1966.

hand-made, hand-grounded, hand-polished, 2 aspherical element surfaces, 5 groups, 1966-1975, 1 meter close-focus.

Not many have been produced and the reason this lens was discontinued and replaced with the f/1 NON-Aspherical version is because HALF of these lenses were trashed because back then Leica has no way of testing the lens until it was completed and assembled. They had a 50/50 success rate and it was a very hard and challenging lens to produce. Legend goes like this. (?) 

This 50mm f/1 replaced the earlier LEICA NOCTILUX 50mm f/1.2 aspherical (1966-1975)

which was the world's first production aspherical camera lens.

The 50mm f/1 NOCTILUX-M lens is not aspherical.

This 50mm f/1 is a conventional spherical design, using special high-index glass to get its performance.

This f/1 lens was in turn replaced by the new LEICA NOCTILUX-M 50mm f/0.95 ASPH in 2008,

which is aspherical once again.