Hacking Nikon L35AF lens for Leica M?

alanchin

alanchin

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What will matter is where the aperture is in relation to the optical block. There's no space between the glass elements to allow the aperture to function, and the whole thing is encased in plastic anyway. I don't have a J-12 anymore, so I can't measure it for you, but if the aperture is far enough back it might work. I have a feeling, however, that it won't be; remember that the I-50 body I used is collapsed, putting the aperture well inside the body.
 
I adapted one to a Kiev J-12 as it's shorter to begin with. Used a cheap 6-bit conversion flange. I don't know if you would be better off starting with a l39 lens body, I had to machine most of the parts and make 2 from stock (flange to lens barrell adapter, RF cam). Regardless of J-12 style you at least have to lathe down the lens plastic bit to fit deep enough in the housing that has the aperture mechanism in it.
 
FrankS said:
I'd just use it the way Nikon intended. It's not a bad little camera.

Now, a Minox 35 lens is a different story.
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Agreed. I would feel bad cutting up my trusty L35af. although i applaud all you guys who do these conversions, love seeing new things.
 
I believe (correct me if I'm wrong) that the Minox lens is a Tessar-type. If so, it is probably capable of better sharpness than the Nikon, and perhaps a bit more contrast. The Nikon lens is a Sonnar-type, unusual (unique?) in such a wide focal length, and offers a unique look. That was my motivation for selecting it over other options.

Oh, and mine came from a camera of dubious operational reliability for which I paid $3 (IIRC), so don't worry about my having hacked up a usable camera.
 
I am actually in the (long) process of converting the nikon l35AF 35/2.8 to m-mount. Rather than looking for the perfect donor I am taking to route of 3d printing an interface for a separate aperture, helix and the lens. Work in progress:

U14380I1484175811.SEQ.0.jpg


U14380I1484175814.SEQ.1.jpg


U14380I1484175816.SEQ.2.jpg


It's been a worthwhile approach for the minoxar lens I did earlier. The challenge is, as always, getting the infinity focus right. I'm pretty happy with the results though!

U14380I1484175817.SEQ.3.jpg
 
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I didn't use it on a M but I hacked a L35AF lens into an Industar 69 to use on the Fujis.

29030403855_cefd9e3c77_c.jpg


Easy there as I didn't have to worry about rangefinder coupling.

Shawn
 
I have a broken L35AF with a perfect lens...otherwise sure I would use the camera. Thank you all for your replies, the 3D printing route that douwe is going seems to be the best? Where is the aperture assembly and blades coming from? A USSR lens?
 
02Pilot said:
I believe (correct me if I'm wrong) that the Minox lens is a Tessar-type. If so, it is probably capable of better sharpness than the Nikon, and perhaps a bit more contrast. The Nikon lens is a Sonnar-type, unusual (unique?) in such a wide focal length, and offers a unique look. That was my motivation for selecting it over other options.

Oh, and mine came from a camera of dubious operational reliability for which I paid $3 (IIRC), so don't worry about my having hacked up a usable camera.
Click to expand...

$3!..best bargain ive seen =) ... i guess im just imagining my working L35 getting cut up even though it works perfect. And i paid $8 some years ago haha

Maybe if i find another one for dirt cheap (is dirt still cheap these days?), i might buy it to do this mod.
 
@douwe Thank you for the link! How did you know which iris mechanism is the correct one? Also, in your photos there is the brass (?) helix...where did that come from? Are you contemplating rangefinder coupling or scale focus?

@Alfonso Yes, with a J-12 in Contax mount you have to do all that lathing -- but with the LTM version, as you mention, wouldn't the only work be getting the L35AF glass to fit in there at that correct distance once you've removed all the original glass? That is, wouldn't the existing rangefinder coupling for the 35mm focal length remain intact and correct? As we would be simply replacing one set of glass elements with another?

Thank you all for the great info and responses. Certainly the conversion to a mirrorless mount rather than Leica M would be simpler, not requiring rangefinder coupling. Perhaps this is the wiser approach -- now, just have to get my hands on a Sony A7!
 
alanchin said:
Yes, with a J-12 in Contax mount you have to do all that lathing -- but with the LTM version, as you mention, wouldn't the only work be getting the L35AF glass to fit in there at that correct distance once you've removed all the original glass? That is, wouldn't the existing rangefinder coupling for the 35mm focal length remain intact and correct? As we would be simply replacing one set of glass elements with another?
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I'm pretty sure the aperture doesn't sit deep enough in a LTM mount Jupiter. It would be extremely helpful if someone unscrewed his/her l39 J-12 rear element and measured the distance from aperture blades to mounting flange. We could then figure out how much the aperture housing needs to go inwards. There's ~0.2-0.5mm of shims there, but removing them isn't likely enough so some part needs to be machined. Likely the inner part of helicoid at least.
 
@alfonso: right! I actually don't own a J-12, and come to think of it, unless I find one with destroyed glass, it's rather a too high quality lens to decommission for a hacked L35AF lens, not an under $10 piece of gear...

@douwe : So it really looks like you have the potentially simplest plan? I don't own Sony full-frame or Fuji, but do have two micro 4/3 cameras. SO, my best bet is build this for micro 4/3...

I need to:

1) Get the lens out of the broken L35AF -- any advice on how to do this best?
2) order correct iris mechanism
3) order an appropriate focusing helicoid, a M42-M42 should do, or M39-M39...will hunt around.
4) DESIGN and PRINT 3D housing that screws into this helicoid -- who has the expertise for this? Douwe, would your existing design work as a basis for a micro 4/3 conversion? Would have to factor in thicknesses of adapter and focusing helicoid.
5) mount onto m42/m39 -> micro 4/3 adapter

Without need for rangefinder coupling and with off the rack iris mechanism and focusing helicoid, this should just be 1 3D print, relatively simple?

Thoughts? THANKS!
 
alanchin said:
@douwe Thank you for the link! How did you know which iris mechanism is the correct one? Also, in your photos there is the brass (?) helix...where did that come from? Are you contemplating rangefinder coupling or scale focus?
Click to expand...

Well, since I took the donor l35AF apart, I could take a look at its shutter/aperture mechanism. The shutter/aperture blades sit in front of an opening with a certain diameter. I assumed this diameter forces the maximum aperture to f/2.8. The iris that I bought has a larger diameter, so I should be fine.

Interestingly, the lens in the L35AF moves when focusing but the shutter and aperture are stationary. This would perhaps explain some of the reports of fairly heavy vignetting: the closer the lens focuses the farther it moves away from the aperture behind the optical cell. Just a theory on my part...

The helix I took from a broken yashica electro 35 GT. The post-mortem wasn't pretty. It's a nice sturdy and wide helix though. I'm still looking for a helix that is wide and has little travel. I have a fuji tiara 28mm f/3.5 lens that is my next candidate for conversion!
 
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alanchin said:
@alfonso: right! I actually don't own a J-12, and come to think of it, unless I find one with destroyed glass, it's rather a too high quality lens to decommission for a hacked L35AF lens, not an under $10 piece of gear...

@douwe : So it really looks like you have the potentially simplest plan? I don't own Sony full-frame or Fuji, but do have two micro 4/3 cameras. SO, my best bet is build this for micro 4/3...

I need to:

1) Get the lens out of the broken L35AF -- any advice on how to do this best?
2) order correct iris mechanism
3) order an appropriate focusing helicoid, a M42-M42 should do, or M39-M39...will hunt around.
4) DESIGN and PRINT 3D housing that screws into this helicoid -- who has the expertise for this? Douwe, would your existing design work as a basis for a micro 4/3 conversion? Would have to factor in thicknesses of adapter and focusing helicoid.
5) mount onto m42/m39 -> micro 4/3 adapter

Without need for rangefinder coupling and with off the rack iris mechanism and focusing helicoid, this should just be 1 3D print, relatively simple?

Thoughts? THANKS!
Click to expand...

You are besically spot on. The critical part is to figure out how close the lens needs to be to the sensor. You'd need to adjust the 3d print according to the thickness of the helicoid and the flange-to-sensor distance of fourthirds.

In short:

~35mm + thickness of 3d print = 4/3 flange-to-sensor + thickness helicoid

hope that makes sense!
 
More research progress:

There is a M42 to micro 4/3 focusing helicoid:

https://fotodioxpro.com/products/m42-mft-p-macro

So that reduces one step -- the unit of lens + iris mechanism just needs to screw into this helicoid (if it's not too thick to achieve infinty -- I've written Fotodiox asking them to tell us the thickness of the adapter).

@Douwe : are you willing to share the design of the 3D mount that you've made? As a starting point for this?

THANK YOU
 
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