Lens Rear

I figured it was time for a macro of some mechanical/technical device. Those sorts of things tend to be .. um ... shiny. I love shiny - shiny glass, shiny metal. I'm not all that particular, really.

Aaaaanyway this is the Nikon F mount and rear-most element for a Sigma 17-70mm 1:2.8-4.5 Macro HSM lens. It was just sitting there on the desk, looking shiny ... and I needed a blip, you see ... and so I blipped it.