Yashinon M39 conversion

[mike_j]

We often say that the Yashinon f1.7 lens is a good performer, but how good is it?

I have a scrap Electro 35 which I have cannibalised to keep my GTN running and am toying with the idea of converting it to Leica M to use on my Bessa R2. A quick check of the film to rear element dimension suggests that it is practical and I have enough of a model engineering workshop to turn up adaptor/spacer rings (I'd use a cheap Leica M to M39 adaptor as a base) I'd strip out or deactivate the shutter and time delay, just use aperture and focussing. I doubt if I will be able to couple the rangefinder but zone focussing will serve

What do you think - is it worth the effort?

 

[b1bmsgt]

Sounds like a fun project. It'll keep you off the streets and out of the bars for a while if nothing else... 😀

Russ

 

[jody]

If you do this provide details I would like to do something similar.

 

[David Murphy]

We often say that the Yashinon f1.7 lens is a good performer, but how good is it?

I have a scrap Electro 35 which I have cannibalised to keep my GTN running and am toying with the idea of converting it to Leica M to use on my Bessa R2. A quick check of the film to rear element dimension suggests that it is practical and I have enough of a model engineering workshop to turn up adaptor/spacer rings (I'd use a cheap Leica M to M39 adaptor as a base) I'd strip out or deactivate the shutter and time delay, just use aperture and focussing. I doubt if I will be able to couple the rangefinder but zone focussing will serve

What do you think - is it worth the effort?

Go for it - sounds fascinating. I have heard of other, similar conversions, where the mechanical shell of a damaged LTM lens is used with the optics replaced. That gets RF coupling.

 

[mike_j]

This is getting 'non trivial' ie:- difficult.

I got the lens out of the camera without too much trouble though I had to drill out the screws holding the lens to the lens panel. The screws were sealed and totally immovable.

I have managed to strip the shutter out more by brute force than science because I just couldn't dismantle to shutter level - the best web guide I could find seems to deal with a slightly different model and made it look easy - it wasn't!

I now have to turn down the camera body mount by 1.2 mm which should be easy enough if I don't distort the helix ring in the lathe and also remove about 5mm of metal from the back of the lens mount. This is part of the casting which carries the shutter wind rod and various wires. The problems are that I must avoid damaging the helix and the rear lens element which I can't remove and find a way of mpunting the lens body in the lathe without cosmetic damage.

On the plus side I have taken a few shots on my working GTN with a similar lens and cannot tell the results against identical shots with the excellent Jupiter f2 50mm on my Bessa R2. These J8s are very variable but when they are good they are very, very good.

Happy days!