Repair nikkor-s 50/1.4 mount

[Srono]

Hi everyone,

I got a lemon purchase from evil bay. The piece of metal (marked red in the photo below, photo was taken from internet, thanks to Ken Rockwell) to stop the lens in mounted position was broken.

Is there any simple fix for this? Thanks!

 

[Livesteamer]

Can you send it back? Joe

 

[Srono]

Thanks everyone! I cannot send back this time as it was delivered to quite long back. I could not check it at the time of delivery. 🙁

 

[Highway 61]

There is an easy fix. This won't replace the broken tab but this has proved to be quite satisfying.

Just slightly bend out the three flanges of the lens bayonet so that the lens mounts very tightly on the camera, and the broken tab won't be an issue. A friend of mine has been doing so for years with a similar Nikkor-S 50/1.4 I had given to him and the lens never come off by itself.

You have to proceed exactly as explained here.

Note about why the tab sometimes breaks : this is due to a misalignment of the long spring of the camera mount (in which the tab engages and then locks). Just before the tab notch, there is an hole in the spring, and there is a grub screw underneath. When you mount the lens the spring is pushed towards the camera body by the lens tab and during the brief spring forth/back action, the grub screw fills the spring hole. If the spring isn't 100% properly aligned any longer (this can happen if the two small screws holding the spring in place have come loose a little bit) then the spring surface hits the grub screw when you mount the lens ; the spring cannot be pushed towards the camera enough, and as a result the lens tab instantly breaks, especially on the black Nikkors 50 (the tab is thinner than on the previous chrome versions of the same lenses).

This is how I myself broke the tab of the lens I gave to my friend later.

 

[Srono]

Thanks Highway61, it is exactly the black 50/1.4 i have. It is sad since its optic is good. I will try to do the same as you suggested. I was thinking to just find a way soldering piece of metal to it. I also thought of getting donor part from a cheap jupiter lens but i need to confirm the similarity by dissemble the lens first.

Or maybe i just get an amedeo adapter and glue this lens with it so it can used for leica M 🙄

 

[Highway 61]

Thanks Highway61, it is exactly the black 50/1.4 i have. It is sad since its optic is good. I will try to do the same as you suggested. I was thinking to just find a way soldering piece of metal to it. I also thought of getting donor part from a cheap jupiter lens but i need to confirm the similarity by dissemble the lens first.

Or maybe i just get an amedeo adapter and glue this lens with it so it can used for leica M 🙄

You definitely cannot fit the Nikkor-S optics barrel in a Jupiter casting.

Have a look here at Vickko's thread about his new (to him) Zunow 50/1.1 lens in Nikon S-mount. On the Zunow lens the tab looks to be consolidated by something metallic and located between the tab and where the lens housing becomes to get fat. This may be the beginning of a good sketch to attempt to successfully repair your broken tab.

 

[Srono]

You definitely cannot fit the Nikkor-S optics barrel in a Jupiter casting.

Have a look here at Vickko's thread about his new (to him) Zunow 50/1.1 lens in Nikon S-mount. On the Zunow lens the tab looks to be consolidated by something metallic and located between the tab and where the lens housing becomes to get fat. This may be the beginning of a good sketch to attempt to successfully repair your broken tab.

Yes!! I like Vickko idea. It looks pretty easy to implement. I will post result when done. Thanks again!

 

[aoresteen]

I'd send it to DAG. If anyone can sort it out Don can.

 

[Vickko]

Yeah, I actually modified the tab, replacing the actual tab part with a brass lug, but still have the plastic reinforcement behind it.

Works perfectly.

And also found out why the tab is necessary.

My lens has a somewhat stiff aperture, so when you turn the aperture, the entire lens can turn. The tab locks the lens into the focus mount. At least when you turn the iris, you turn the focus ring. Worse case is the lens turns in the mount, and then you have to be really careful that the lens doesn't dis-mount. You don't want to drop the lens.