Tag Archives: Leitz

Summicron-M collapsible

I got a hold of a Leitz 5cm f/2 Summicron-M collapsible lens … one that was in really bad condition, which was the only way I could afford grabbing this type of lens. I have to say (and I knew for a long time) Leica M stuff is EXPENSIVE (I thought the LTM was over priced).

I did not do a complete dissasembly … like getting at the focus helicoid.


The lens is actually not that difficult to work on, but just requires a bit of pre-info … since you really don’t want to damage a Leitz.

The front element is very soft so it is noted on being very easy to scratch when cleaning. This one has heavy haze and fungus.





DSC00531To get to the aperture blades you can just unscrew the entire front group off.

Getting between the elements of this front group is something I did not even attempt to do.







DSC00532You can remove the rear cap section, but you have to do one thing first. There is a small screw in the side of the lens barrel, loosen that first

It is a brass screw, so watch out !!!







before using your spanner wrench to unscrew the rear retaining ring.










The collapsible lens rides on two slots, and the rear focus ring has two bearings inside it … so try not to loose them … and when putting it back together you have to line up the slots.

You can see the two bearings (the left one is missing in this shot).





Here is a picture of the end cap attached to show how the slot should line up.

The encap goes on after placing the focus ring on … so you will have to eye ball it.

Then screw the retaining ring back on with the spanner wrench without turning the end cap … then secure the side screw.


Cron the destroyer …

The Leitz 50mm lens went through many different iterations since 1924, starting with the Anastigmat designed by Max Berek … the Summar was the first of the f/2 line in 1932, then Summitar, then finally the Summicron.

The Ernst Leitz Wetzlar Summacron 50mm (5cm) f/2.0 first production M-mount started 1954. The Leica part name for the m-mount version is SOOIC-M (don’t ask me about that). 7 elements in 4 groups … that’s a lotta glass !!! The original version started as a collapsible, later 1956 they also producted a rigid body.

Early 50mm Summicron’s had lens elements, made by Chance Brothers & Co., that had thorium oxide in it … very low radioactivity and it eventually turned the lens little yellow/brown over time … they quickly switched over to their own lanthanum oxide formula.

Marco Cavina has a great website about Leica, though it is in Italian … but I don’t think you will have any problems finding reading matrial about anything Leica.

Now I am not a Leica person, I was caught offguard when people use the suffix to talk about various lenses … and this one being the Summacron 50mm (5cm) f/2.0, it was refered to as a cron. It appears that a Summacron refers to the f/2.0 aperture size ? … obviously I am a Leica newbie … so what do I really know.





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