Dante221 Posted October 19, 2012 Share #1 Posted October 19, 2012 Advertisement (gone after registration) Hello All! Forgive the noob question: What was the purpose of the button on some of the Summicron 50mm lenses that "locked" the focus at infinity? Thanks for your patience! Dante Link to post Share on other sites More sharing options...
Advertisement Posted October 19, 2012 Posted October 19, 2012 Hi Dante221, Take a look here re older Leitz lenses:. I'm sure you'll find what you were looking for!
bill Posted October 19, 2012 Share #2 Posted October 19, 2012 Welcome Dante It does exactly what you have said. It locks the lens at infinity so that you do not put strain on the focussing helicoid when changing lenses. Regards, Bill Sent from another Galaxy Link to post Share on other sites More sharing options...
earleygallery Posted October 19, 2012 Share #3 Posted October 19, 2012 The focus lock button is rather curious. As Bill says, it makes changing lenses easier/safer as the focus ring is locked and can be gripped when changing lenses. However, the earliest fixed lens Leicas also had this feature.....I think it was also to hold the lens in place when extending or collapsing a lens (such as was fitted to those cameras, and the later Elmar 5cm etc). Also the button doubles as a focussing tab. So the infinity lock as served several purposes! Link to post Share on other sites More sharing options...
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