[mst]

The black paint version is a limited edition, which was introduced in 2000 to match the Leica M6 black paint, also called the "Millenium Edition". Leica often builds limited editions of their lenses (and cameras), which usually sell soon and normally become collectors items.

It's not that obvious in the images, but the black paint lens has a glossy finish, while the regular anodized version has a somewhat "silky" surface. Additionally, the black paint lens features red markings, while the anodized lens shows the normal yellow/orange markings.

Optically, the lenses are identical. The main difference is that the anodized version is made of aluminum, while the black paint version (and also the silver chrome version) is made of brass. That's why those two versions are quite heavy (for such a small lens).

-- Markus