Yashica GSN Butchery

Maeda

Mu-43 Regular
Joined
Dec 1, 2010
Messages
87
You need to create the 'flange' from a ring-shaped section of the front plate of the Yashica body which contains the two brass tabs that allow the lens to slide without turning : reduce it in diameter until it will fit into/onto your C-adapter. You can then drill and tap that 'flange' and screw through from the back of the C-adapter.
Thanks for the status update.

Do you reduce it enough so that it fits in the inner section like this?

View attachment 153547

or the wider portion?

...unless you have any thoughts on how to put a C mount onto the Yashica body as well so I can mount some unused lens on it.:smile:
10$ + shipping buys you another on evilbay. Keep the one with sentimental value and rip apart a different one. :biggrin:
 

Ulfric M Douglas

Mu-43 Hall of Famer
Joined
Mar 6, 2010
Messages
3,709
Location
Northumberland
The 'flange' is too broad to fit into the inner section, and mine is too broad to fit into the outer rim. My 'flange' sits on the front of the outer rim with a section inside it. You will understand once you have removed the lens and front plate section and have started to reduce the 'flange' diameter. It is a big lens really.
Subscribe to see EXIF info for this image (if available)

I built up an inner ring using epoxy putty. This new section fits inside the outer rim of the adapter, giving two faces (and 'L'-section) for my superglue solution.
The 'flange' (section of original camera front-plate) I needed to file down in thickness to achieve perfect focus at infinity.

I used a VERY dead Yashica camera.

Here is my favourite picture ;
https://www.mu-43.com/f57/mam-son-portrait-woods-6596/
 

Maeda

Mu-43 Regular
Joined
Dec 1, 2010
Messages
87
Ah, thank you for that size comparison. That makes things quite a bit clearer.

..and the linked image is a great image straight out of the camera. It gives me a lot of hope that this process is worth it.

I love to tinker. For some reason this lens + the promise of some DIYing, seems more attractive to me then just plunking down for a Jupiter 8.
 

Maeda

Mu-43 Regular
Joined
Dec 1, 2010
Messages
87
Just a little note for anybody else that's going to attempt this.

Dissemble the lens from the front, and when you get to the shutter, remove it and put the lens back together.

THEN remove the mounting plate from the camera. There are 4 screws on the camera body.

---------

Somehow when I unscrewed the back of the lens (brass ring is reverse threaded) I must have ovaled it or something, as I couldn't get anything back together.

When I finally did get the back to screw on, everything was frozen up. After that I tried to give it a little more love, with the vice, and thats when things really started to go down hill.

What really makes me mad is that I had everything together except the last ring on the back to mount to the camera body plate and now I have nothing.

I have to order another Yashica now.. :mad: But at least I know the procedure from here on out...
 

jwestra

New to Mu-43
Joined
Dec 6, 2010
Messages
1
Very good idea and nicely done.

Do you guys think this can also be done with the Olympus PEN fixed lens cameras?
I think these lenses would fit the e-p1 very nicely.
Some nice suggestions:
Pen D , 32mm f/1.9 lens
Pen D3, 32mm f/1.7 lens
Pen EE.D, 32mm f/1.7 lens

(maybe a good idea to share other camera's with nice fixed lenses)
 

Maeda

Mu-43 Regular
Joined
Dec 1, 2010
Messages
87
Subscribe to see EXIF info for this image (if available)

_1010002 by Jim Argyle, on Flickr

Subscribe to see EXIF info for this image (if available)

_1010154 by Jim Argyle, on Flickr

View attachment 153985

Success? Almost.

I can't get the thing to focus to infinity now. A little more grinding is in order. :biggrin:

This is A LOT of work. It was more work then I was prepared for, but I swear this thing is sharper then my 20mm... or maybe thats the metal shavings in my brain talking...
 

Ulfric M Douglas

Mu-43 Hall of Famer
Joined
Mar 6, 2010
Messages
3,709
Location
Northumberland
That's the metal shavings ... that got into the back of my lens assembly ...
The lens is so easy to take apart it was no trouble.

Bit more filing ... bit more ... little bit more ...

My aperture movement is unpleasantly scratchy : what's your's like?
 

Maeda

Mu-43 Regular
Joined
Dec 1, 2010
Messages
87
My aperture is SMOOTH like butter. You have to clean the brass portion really well, so that when you put the snap washer thing on, it's nice and tight.

That snap ring is a bitch though.
 

madmaxmedia

Mu-43 Veteran
Joined
Feb 20, 2010
Messages
346
Bumping an old thread here, but Yashica Electros are still cheap and this is a nice little mod for mirrorless cameras.

I have been following Jackslai's Flickr gallery for modifying this lens for my NEX, and he clarified for me how he was able to fix the lens mount for proper focusing, without having to use that brass base plate. This is a good option if you don't have the ability to cut that piece down to size, and I think takes a lot less time. There is more precision involved in that the drill hole locations better be right.

He drilled 3 holes in the cmount adapter to mount the lens to the adapter, using the same screws that normally mount the lens to the brass plate- this part you can gather from the Flickr photos. So firstly, the 'base ring' for focusing is fixed relative to the cmount adapter.

To fix the inner section of the lens, he put a guide screw through one of the holes at the base, you can see the holes here:
COLOR - Yashinon DX 45mm F1.7 | Flickr - Photo Sharing!

He also drilled another hole through the cmount adapter for the guide screw. Now the inner section is fixed in relation to the cmount adapter. So now both inner and outer sections are fixed to the adapter, and the focusing mechanism will work.

I haven't finished this project myself yet, having just removed the lens from the brass plate.
 

groms

Mu-43 Rookie
Joined
Jun 24, 2012
Messages
10
Hello
I'm also going to try this conversion, but I still haven't figured out how to adjust for infinity focus in Jackslai's way of mounting. Have any of you figured this out?
 

madmaxmedia

Mu-43 Veteran
Joined
Feb 20, 2010
Messages
346
I still haven't gotten that far yet. But instead of grinding down metal, we'll probably need to add spacer. Here is what Jack told me-

"I will try my best to answer your question. I want to make clear, total three flat screws and one long screw and one C-mount adapter, no other parts for this conversion.
I did not ensure right registration distance for the lens, I used screen live view to make sure infinity focus is included in the focus range, I did the fine adjustment for infinity focus on final step."

It sounds like instead of using the original 3 short screws that fixed the lens to the brass plate, he used slightly longer screws. This way you can basically 'fix' the lens at distance from the cmount adapter. In any case, he was able to adjust after he screwed it all together. So I will worry about perfect calibration later. I just want to finally shoot the damn thing and look at the images- I always liked photos from the Electro.
 

madmaxmedia

Mu-43 Veteran
Joined
Feb 20, 2010
Messages
346
Okay, I've finally opened up the lens and de-activated the shutter. I've played around with the lens by holding it in front of my NEX-5N with the c-mount adapter screwed in. For proper registration distance I think I need about 1mm spacer in between the lens and the c-mount adapter. That's a very rough estimate- I don't have the lens in hand right now.

I really wish I could get the original 45mm FOV, but the limited handheld results do seem promising. The lens is somewhat soft at f 1/.7, but gets pretty sharp and contrasty by f/2.8 and I think will be better than the Sony kit zoom at equivalent focal length. More than anything I am wondering how the lens will render on digital, there's something about the Yashica Electro film images that are very appealing to me.

I also have a little Petri Racer with 45mm f/1.8 lens, the lens is definitely smaller but not sure if it's as good as the Yashica. This one works though, so I'm less likely to take it apart.
 

Jorg.S

Mu-43 Regular
Joined
Jul 14, 2011
Messages
170
Location
Raleigh North Carolina
God this camera brings back great memories.
It was one of my first rangefinder cameras and I had bought the whole kit and accessories with the kit when I bought it oh so many years ago.
It came with two screw on converter lenses an some other stuff lol.
I now have to go and see if I can find some old prints of some film I had shot,
I took this camera with me everywhere for like 3 years and thought I had a Leica.
I do remember that I sold it about 3 or 4 years ago and it was still working great but I had to buy some rig to get the battery power and the meter was alway off a little after that conversion.

Anyway carry on folks I was just getting nostalgic after reading this here.
 

zorki1

Mu-43 Regular
Joined
Aug 26, 2010
Messages
47
How I did it

I did mine a little differently. That center piece looking from the rear that slides up and down the brass tabs, I shortened it in my mini lathe as it would hit the c-mount adapter when extended out. You can screw that part in or out to get the infinity close then install tabs. Lots of trial and error, then, I screwed the c-mount to the former lens mounting plate from the Yashica (i ground it down to round) with 00-90 flat head screws which I had drilled and tapped for. I used a little larger bit to countersink the heads. The last thing, since infinity was close, was to focus to infinity using an slr as the colimnator, then loosen the foucus ring on the yashica lens and move it to the infinity mark. Hope this is helpful.

Forgot to mention, I had to bend those brass tabs down since I had shortened the center piece,or else they would run out.

Subscribe to see EXIF info for this image (if available)



Subscribe to see EXIF info for this image (if available)
 

ean10775

Mu-43 All-Pro
Joined
Jan 31, 2011
Messages
1,203
Location
Cleveland, Ohio
Real Name
Eric
I have an Electro 35 GT that has the POD issue as well as an electrical short. I'd love to do something like this but lack the skill. I don't suppose anyone would consider doing it for me for a fee?
 

groms

Mu-43 Rookie
Joined
Jun 24, 2012
Messages
10
Well, this conversion is certainly not going my way. I´m stuck in disassembly; the locking ring keeping the focusing mechanism to the shutter is completely stuck. It´s stuck so hard that it´s bent my spanner and the ring is full of cuts and shavings from high-tension slipping.
So I thought maybe I´d be able to work from the front of the lens, but the front lens group that´s supposed to unscrew as a unit, didn't. I had to remove it piece by piece, and still the "cylinder" that the lenses are fastened onto is stuck, and I don´t know what to do to loosen it without damaging it.

So I´m pretty bummed out here. Any suggestions, anyone?
 

zorki1

Mu-43 Regular
Joined
Aug 26, 2010
Messages
47
If you are refering to the ring around the rear element, remove the rear element and see i you can get a soldering iron tip down to the ring and heat it up, that should expand it and come loose. I dont have mine in front of me so I dont remember how much room there is.
 

Latest posts

Links on this page may be to our affiliates. Sales through affiliate links may benefit this site.
Mu-43 is a fan site and not associated with Olympus, Panasonic, or other manufacturers mentioned on this site.
Forum post reactions by Twemoji: https://github.com/twitter/twemoji
Copyright © 2009-2019 Amin Forums, LLC
Top Bottom