[doubice]

Thanks, JC!

My memory was refreshed after reading your post. I do recall the little pin that was depressed when the goggles were slid into position and thus unlocked the focusing mount. Yes, the only reason for the goggles' removal was to make it easier to store the lens. It would not focus correctly without the goggles on any M Leica - that is why the focus was locked when the goggles were removed.

Basically the same idea as the locking system on the DR Summicron - you can only focus in the close range when the goggles are attached and cannot focus further than 1 meter with the goggles in place.

Best,

Jan