Toronto. A few days ago George Dunbar sent me more ads by email. Amongst them was a Leitz ad for its famous 50mm Summicron in a collapsible mount.
I wrote back to George saying, “The seven element 5cm summicron ad brings memories. I have an iteration three or four times newer than that first model. The number of elements was reduced to six and recalculated at least twice.
“The one I have is a closer focusing, higher contrast and slightly sharper version with the fine focussing knurling in a light black anodized mount without an infinity lock. I bought it in 1972 with my M4 from Korda in Montreal. It came with the lens hood too (after I had an argument with the clerk and had to show him in the Leitz catalogue that the lens came with the hood).”
This lens replaced all previous standard lenses for the Leica. The famous Elmar f/3.5 was replaced by an optional f/2 Summar. Post war screw mount cameras and then M-mount cameras used an f/2 Summitar and then an f/2 Summicron as a standard lens. Early models were collapsible (fixed mount Summars are rare and expensive) while later ones like mine were fixed mounts with lens heads that could be unscrewed and used separately for close-ups.