Leica 50mm Summicron - Is this Normal?

[Dovaras]

Is this normal? I just purchased my first Leica (M7) along with a 50mm/f2 Summicron. The lens is used but good condition. When I went to mount it I noticed that the rear brass inner barrel appears to be chipped right where the bayonet curves down. I’ve attached a photo below. The chip follows the bayonet curve so closely that I’m second-guessing myself as to whether this is correct or not. Can someone take a look at the back of their lens to see if the brass inner barrel looks like this?

Thanks,

ND

 

[JLP]

Congratulation on your M7 and don't worry about the "Chip", it is normal. The the cam for paralax adjustment is moving in and out in that space.


jan

 

[phaedrus]

All's as it should be there. The helicoid needs to be cut down following the steering curve of the bajonet.

 

[Dovaras]

Thanks a ton! I'll sleep better tonight. I spent the day wondering how I was going to explain to my wife that I just paid $800 for a broken lens! Regards, Nick

 

[Eric Rose]

They're all pulling your leg. The lens is horribly broken. Just send it to me for a decent burial.

 

[Uhner]

They're all pulling your leg. The lens is horribly broken. Just send it to me for a decent burial.

Damn, I have three with the same or similar conditions. If you promise to give them proper burials under headstones made from original MP or M3 top-plates I might consider to send them to you instead of taking them to the Leitz burial grounds in Wetzlar.

 

[Sirius Glass]

Did anyone notice how nicely machined the fracture was?


Steve

 

[Dovaras]

Ok.. at the risk of being laughed at... please see attached picture. This is also a Leica 50mm/2 Summicron. Look at the inner copper ring, you can see it through the nickel colored bayonet curve. This is not true on my lens (see photos in 1st post). The inner copper cylinder on my lens seems to have been shaved down. I'm not talking about the machined curve in the lens mount, i'm talking about the copper colored ring behind it. The copper ring in this photo appears to be the same height all the way around, on mine it's shaved down to follow the curve of the mount.:confused:

 

[Uhner]

I’m sorry I was a bit daft in my previous post. Try focusing the lens and you will se the “copper ring” moving up and down. You will be able to replicate the appearance of the third picture you posted.

Cheers

Claes

 

[Uhner]

I might add that this movement enables the rangefinder in the camera to know the focus distance of the lens.

 

[Dovaras]

I checked.. you're right.... I'm done....

 

[lens_hacker]

Ok.. at the risk of being laughed at... please see attached picture. This is also a Leica 50mm/2 Summicron. Look at the inner copper ring, you can see it through the nickel colored bayonet curve. This is not true on my lens (see photos in 1st post). The inner copper cylinder on my lens seems to have been shaved down. I'm not talking about the machined curve in the lens mount, i'm talking about the copper colored ring behind it. The copper ring in this photo appears to be the same height all the way around, on mine it's shaved down to follow the curve of the mount.:confused:

I noticed the same is true on my Type 2 Rigid Summicron. The Leica Rangefinder is calibrated for 51.6mm. The focal length of individual lenses may deviate slightly, and most manufacturers just leave the RF cam flat. The Leica cam is milled to take the deviation into account. By the looks of my RF Cam, the difference is about 0.1mm. The cam is milled to correct for the slight deviation in the focal length of this particular lens from 51.6mm. I suspect this was required when the minimum focus of Leica lenses was brought in to 0.7m from the old 1m standard of the M3 generation lenses.