Ellis420
Newbie
Hi everyone, I'm Ellis, I study Engineering in southern England, I'm also very interested in analogue photography. I've been working on this project for a few weeks and so thought I'd write a post detailing a few things about it, it's not finished yet but it's not far away.
Late last year I converted a Minox 35 lens to Leica for an assignment, theres an article on JCH I wrote if you want to check it out here: http://www.japancamerahunter.com/2017/01/camera-geekery-minox-35gt-lens-conversion/. The minox conversion is one of my favourite lenses and I use it day to day as I would me other lenses.
Recently I started looking into making new lenses, I converted a Rollei 35 lens via a 3D printed part, It works great but I never got around to machining it as it became abit boring. Instead I started looking at the Yashica Electro, I'd seen the MS-Optics conversion which used a new housing, Mr. Miyazaki's work is incredible and I look up to his work very much so. I wanted to try the conversion myself so I bought an old broken yashica electro.
I immediately tore the camera apart and took the lens out, after a few measurements I was convinced I would be able to convert the lens, I wanted to convert a lens that would be RF coupled and so thought it would be possible when I first looked at the lens, more on this later.
I started by tearing out the shutter parts from the lens, aswell as anything else that wasn't needed. The aperture blades fell out whilst doing this and it took a very very long time to figure out how they go back in.
https://ibb.co/mjD2iQ
I put the useful parts of the lens bak together and started working on the design for the conversion, I worked on this for a few weeks here and there, I was preparing for exams at the time so it didn't have all my focus. It took a long time and many different designs to come to something that would work, heres a model I made in Solidworks.
https://ibb.co/dHSTOQ
This is a model of the back of the lens, the 2 grey parts are to me machined form scratch and the other 3 are original parts, all of which require extra machining
The Yashica lens sits quite close to the mount so this means removing alot of material from the pre-existing part of the lens, below is the part which basically attaches the main part of the lens to the helicoid part, I've shown a before and after image to show just how much material was removed.
https://ibb.co/kygNiQ
https://ibb.co/jez8OQ
I now machined the mount for the lens, I have my own Leica mount design which is pretty much perfect so I just added the different tabs and cutouts necessary into the design, this part was hard to machine, lots of different features. I actually made the first one but the tab which selects framelines was filed too short, meaning it selected 35mm framelines, so I went back and made another, It was alot faster the second time, only took an hour or 2.
https://ibb.co/fKAF3Q
https://ibb.co/cgt2iQ
I mentioned before that I wanted to make the lens RF coupled, I planned to do this via the black part which I machined, using it to push against the RF cam, however because this lens is 45mm not the usual 52.6mm (I think) it usually is the black edge had to rotate in order to compensate via a slope, the only rotating part was the brass part for the focusing ring, I managed to work a part that fit around everything and could be press-fit into this ring, this required a lot of redesign work and it pains me to put it into 1 simple sentence. This part has about 0.5mm clearance around everything surrounding it and weighs just a couple of grams due to how little material is left on it. Heres an image of the part as well as the brass part is fits in to.
https://ibb.co/mRC3OQ
https://ibb.co/hrRxiQ
Heres an image of everything together, note the first image doesn't feature the cam ring. Theres also a cross-section showing where everything is, I'd image it just looks like a mess of metal parts all together to anyone else but here is anyway.
https://ibb.co/j5KHiQ
https://ibb.co/dj9uV5
https://ibb.co/jt3A3Q
I tested the lens before I came home from university for summer and saw the focus is off, very annoying, fortunately all machining is done so I should be able to finish it without any need to machining equipment.
I saw the lens is only about 0.5m off at closest focus. I put some tape in the film plane of my M6 and tested the focusing yesterday, I moved the whole lens about 0.6mm froward, this seems to be about right, I'm waiting for my fixer to arrive so I can develop some test shots to get the lens perfect, I'm considering buying a fuji x-pro or something to get focus exact via an adapter, any suggestions would be helpful here.
Once the focusing is correct I just need to press in the cam ring and file it to match the focusing distances, this shouldn't be too hard.
So theres when I'm up to right now, heres a photo of the lens on my M6 for a quick preview.
https://ibb.co/n7N1ck
Thanks for reading everyone, I'll post updates as I go along!
Late last year I converted a Minox 35 lens to Leica for an assignment, theres an article on JCH I wrote if you want to check it out here: http://www.japancamerahunter.com/2017/01/camera-geekery-minox-35gt-lens-conversion/. The minox conversion is one of my favourite lenses and I use it day to day as I would me other lenses.
Recently I started looking into making new lenses, I converted a Rollei 35 lens via a 3D printed part, It works great but I never got around to machining it as it became abit boring. Instead I started looking at the Yashica Electro, I'd seen the MS-Optics conversion which used a new housing, Mr. Miyazaki's work is incredible and I look up to his work very much so. I wanted to try the conversion myself so I bought an old broken yashica electro.
I immediately tore the camera apart and took the lens out, after a few measurements I was convinced I would be able to convert the lens, I wanted to convert a lens that would be RF coupled and so thought it would be possible when I first looked at the lens, more on this later.
I started by tearing out the shutter parts from the lens, aswell as anything else that wasn't needed. The aperture blades fell out whilst doing this and it took a very very long time to figure out how they go back in.
https://ibb.co/mjD2iQ
I put the useful parts of the lens bak together and started working on the design for the conversion, I worked on this for a few weeks here and there, I was preparing for exams at the time so it didn't have all my focus. It took a long time and many different designs to come to something that would work, heres a model I made in Solidworks.
https://ibb.co/dHSTOQ
This is a model of the back of the lens, the 2 grey parts are to me machined form scratch and the other 3 are original parts, all of which require extra machining
The Yashica lens sits quite close to the mount so this means removing alot of material from the pre-existing part of the lens, below is the part which basically attaches the main part of the lens to the helicoid part, I've shown a before and after image to show just how much material was removed.
https://ibb.co/kygNiQ
https://ibb.co/jez8OQ
I now machined the mount for the lens, I have my own Leica mount design which is pretty much perfect so I just added the different tabs and cutouts necessary into the design, this part was hard to machine, lots of different features. I actually made the first one but the tab which selects framelines was filed too short, meaning it selected 35mm framelines, so I went back and made another, It was alot faster the second time, only took an hour or 2.
https://ibb.co/fKAF3Q
https://ibb.co/cgt2iQ
I mentioned before that I wanted to make the lens RF coupled, I planned to do this via the black part which I machined, using it to push against the RF cam, however because this lens is 45mm not the usual 52.6mm (I think) it usually is the black edge had to rotate in order to compensate via a slope, the only rotating part was the brass part for the focusing ring, I managed to work a part that fit around everything and could be press-fit into this ring, this required a lot of redesign work and it pains me to put it into 1 simple sentence. This part has about 0.5mm clearance around everything surrounding it and weighs just a couple of grams due to how little material is left on it. Heres an image of the part as well as the brass part is fits in to.
https://ibb.co/mRC3OQ
https://ibb.co/hrRxiQ
Heres an image of everything together, note the first image doesn't feature the cam ring. Theres also a cross-section showing where everything is, I'd image it just looks like a mess of metal parts all together to anyone else but here is anyway.
https://ibb.co/j5KHiQ
https://ibb.co/dj9uV5
https://ibb.co/jt3A3Q
I tested the lens before I came home from university for summer and saw the focus is off, very annoying, fortunately all machining is done so I should be able to finish it without any need to machining equipment.
I saw the lens is only about 0.5m off at closest focus. I put some tape in the film plane of my M6 and tested the focusing yesterday, I moved the whole lens about 0.6mm froward, this seems to be about right, I'm waiting for my fixer to arrive so I can develop some test shots to get the lens perfect, I'm considering buying a fuji x-pro or something to get focus exact via an adapter, any suggestions would be helpful here.
Once the focusing is correct I just need to press in the cam ring and file it to match the focusing distances, this shouldn't be too hard.
So theres when I'm up to right now, heres a photo of the lens on my M6 for a quick preview.
https://ibb.co/n7N1ck
Thanks for reading everyone, I'll post updates as I go along!
