Krosya- well done. I and others would appreciate it if you posted the pictures and instructions for the tear-down.
My Canon P holds coupling with the modified J-3. A quick test is to take the lens off of the camera and check the close-focus of the RF without the lens. If it is much closer than 0.9m, and chances are the threads of the lens are blocking it from achieving close-focus. File the threads down.
Krosya
Konicaze
Krosya- well done. I and others would appreciate it if you posted the pictures and instructions for the tear-down.
I'll have to get them sorted out - I took some photos as I wa doing it, but not every step, so some things I'll have to write out, while they are fresh in my head.
The second time that I worked on a J-3 I decided to photograph everything and write it down. Like how not to spend an hour getting the helical back together.
It's scary how fast the "data" gets lost without writing it down.
It's scary how fast the "data" gets lost without writing it down.
Krosya
Konicaze
Notice anything strange about this photo...
![]()
No shims... but racked out to 0.7m! The Nokton 50/1.5 has been modified internally to allow it focus all the way down to just under 0.7m. Mission accomplished!
The modification was relatively straight-forward without compromising the integrity of the lens in any way. While I did leave a few tracks internally, there is no evidence of the modification externally except for the small notch filed in the LTM mount as shown below.
![]()
With a fabrication of a few tools, I can modify these lens without any trace of the lens ever being tampered with except the notch on the mount. All I need now is to be able to engrave the '0.7' on the meter scale and '2.5' on the feet scale. If the ZM 50/1.5 is made in the same way, this modification could be done to that lens as well.
Having the Nokton 50/1.5 being able to focus as a full range lens from infinity to 0.7m has filled my need/want for a versatile 50/1.4 RF lens and my need/want for a Summilux 50. Instead I am looking for a silver Nokton 50/1.5 to modify as well to go with my new, yet to be bought silver M5.
BTW, I didnt have to make a notch in the mount - at least not yet. I only tried it on RD1S, but no coupling issues at all so far. I'll have to check other bodies though.
ampguy
Veteran
Still too much work for .2 / .3m IMHO. I can get .7m to infinity with a super thin shim on my J3 (tip - rei width membership card ~.2mm or so).
Why can't the Noktons just use a shim, or a fat adapter, as they apparently do vary in thickness?? Infinity - 10 feet is still infinity.
Why can't the Noktons just use a shim, or a fat adapter, as they apparently do vary in thickness?? Infinity - 10 feet is still infinity.
Krosya
Konicaze
Still too much work for .2 / .3m IMHO. I can get .7m to infinity with a super thin shim on my J3 (tip - rei width membership card ~.2mm or so).
Why can't the Noktons just use a shim, or a fat adapter, as they apparently do vary in thickness?? Infinity - 10 feet is still infinity.
I suppose - it's different from person to person - it took me about 3-4 hours to make this modification, but to me it's worth it. Afterall - people pay a huge $$ difference from E43 to E46 Summilux pre-asph just to be able to focus closer, since they say that optical formula is the same.
So, YMMV. I'm loving the new "upgraded" Nokton and no shims or other things to mess with.
semordnilap
Well-known
Mmmmmm.... Please post pictures...! I'm getting more and more interested in this...
P. Lynn Miller
Well-known
Still too much work for .2 / .3m IMHO. I can get .7m to infinity with a super thin shim on my J3 (tip - rei width membership card ~.2mm or so).
Why can't the Noktons just use a shim, or a fat adapter, as they apparently do vary in thickness?? Infinity - 10 feet is still infinity.
I am not sure what you are trying to promote here...
I have said numerous times, that the simplest and easiest, non-destructive, easily reversible method to get the Nokton 50/1.5 to focus to 0.7m is with a shim/extension ring between the lens and camera/M-mount adapter as illustrated here...

With the correct shim thickness, any LTM 50mm can be made to focus to 0.7m with rangefinder coupling. The shim thickness will vary depending on the close focus distance built into the lens. The Nokton 50/1.5 requires a 0.9mm while the Rigid Heliar 50/2 requires a 1.1mm to get down to 0.7m. While I have been making my shims from aluminium, they can be made from an old membership, steel, old DVD/CD, etc.
While you have the shim/extension ring installed, you will not be able to focus the lens to infinity, the focus range will be limited from 0.7m to about 4m. Remove the shim/extension ring and the lens operates as normal.
Brian is the authority on J-3 construction and modification and I am sure he will be happy to contribute to a new thread about modifications that allow the J-3 to focus to 0.7m.
With some metal work, the focus range of the Nokton 50/1.5 be extended to 0.7m without the use of a shim/extension ring. The lens will focus continuously from infinity to 0.7m with a turn of the focus ring. The extra 0.2m was worth taking the time to permanently modify my Nokton 50/1.5.
wintoid
Back to film
I have small kids, who I like to shoot relatively close up, and who like to come straight towards the camera 
One reason I keep coming back to SLRs is that I can focus to .5m with a 50mm lens. If rangefinders only went to 1m, I wouldn't be using a rangefinder camera at all. The difference between 1m and 0.7m is huge for me. I'm watching this thread with great interest, although I am not in the slightest bit handy...
One reason I keep coming back to SLRs is that I can focus to .5m with a 50mm lens. If rangefinders only went to 1m, I wouldn't be using a rangefinder camera at all. The difference between 1m and 0.7m is huge for me. I'm watching this thread with great interest, although I am not in the slightest bit handy...
P. Lynn Miller
Well-known
Nokton 50/1.5 is a modern lens, even though LTM, should have still been made by Cosina with 0.7m. After all, they did make CV 21/4 that is LTM and focuses close.
Agreed... Cosina has no real reason as to why they did not make the 50/1.5 focus to 0.7m from the factory, especially when the 50/1.5 is made to focus to 0.75m.
I also took apart CV 75/2.5 today and tried to make it focus close. It's a whole diffent design inside and I did make it focus a LITTLE closer,but it's really not possible to modify it to go to 0.7m, as far as I could tell.
Did you take any photos of the 75/2.5 apart? If so, would you be kind enough to start a new thread on the 75/2.5, which is rapidly becoming one of my most used lenses. I actually prefer the 75/2.5 to the new 75/1.8. Would be great to get the 75/2.5 down to even 0.9m.
Thanks!
P
Peter S
Guest
Thanks guys for all the info and insight into the experimentation. I have 2 left hands as we say in Holland, but I always enjoy seeing others hacking lenses. As the Nokton has been sold out for a while I wonder whether Mr K. will produce a Nokton 50/1.5 in M mount and at the same time with closer focus. Wouldn't that be nice ?
Krosya
Konicaze
Thanks guys for all the info and insight into the experimentation. I have 2 left hands as we say in Holland, but I always enjoy seeing others hacking lenses. As the Nokton has been sold out for a while I wonder whether Mr K. will produce a Nokton 50/1.5 in M mount and at the same time with closer focus. Wouldn't that be nice ?
That would be nice, but if they follow the same trend - a "new" Nokton 50/1.5-M/close focus would cost extra $200 or so. Based on latest price on Nokton at CmeraQuest - $599 it would make it $800 lens!
Krosya
Konicaze
Did you take any photos of the 75/2.5 apart? If so, would you be kind enough to start a new thread on the 75/2.5, which is rapidly becoming one of my most used lenses. I actually prefer the 75/2.5 to the new 75/1.8. Would be great to get the 75/2.5 down to even 0.9m.
Thanks!
I did take pics and I will post them with some explanations as well. HOWEVER, I wouldnt get too excited yet - the way 75/2.5 is made - there is no way (or at least easy way) to make it focus closer, other than just a very bit. But I'll show what best I could do. Maybe someone handier than me will figure a way to do more?
ampguy
Veteran
just my experiences Lynn
just my experiences Lynn
I'm certainly not trying to take away anything from your or Brian's idea of using the shim. I am excited by what you've found with the shims and spent many hours on my own with both the 50, and a 35 based on your first postings.
I guess what you're not seeing, or believeing from me is that with the J3, it is possible to have a very usable lens that focuses from about .8m to near infnity, and I am assuming (based on the very small shim width compared to yours on the Nokton 50/1.5) that maybe this could translate to the Nokton, all it would take is someone to try a thinner shim, or a certain model of LTM/M adapter from CV).
In fact, I'm saying you can buy a brand new CV adapter from CameraQuest today, and possibly get what I'm getting with my J3, which is about .8m to just before infinity.
One could call that adapter out of spec, or for purposes of this thread, a benefit.
Thanks again Lynn for the awesome idea of using shims. It was fun for a couple of days with the 35, but the real usefulness for me is having a 2nd '50 that I'll know I can use if I don't plan on heavy infinity work, but lots of close work. That's what my J3 is dedicated for right now.
I've owned the Nokton before, and it's a big big lens, next biggest 50 I've owned was the Noctilux 50/1. The J3 is about 1/2 the size, so it's my choice for modding/shimming/using.
just my experiences Lynn
I'm certainly not trying to take away anything from your or Brian's idea of using the shim. I am excited by what you've found with the shims and spent many hours on my own with both the 50, and a 35 based on your first postings.
I guess what you're not seeing, or believeing from me is that with the J3, it is possible to have a very usable lens that focuses from about .8m to near infnity, and I am assuming (based on the very small shim width compared to yours on the Nokton 50/1.5) that maybe this could translate to the Nokton, all it would take is someone to try a thinner shim, or a certain model of LTM/M adapter from CV).
In fact, I'm saying you can buy a brand new CV adapter from CameraQuest today, and possibly get what I'm getting with my J3, which is about .8m to just before infinity.
One could call that adapter out of spec, or for purposes of this thread, a benefit.
Thanks again Lynn for the awesome idea of using shims. It was fun for a couple of days with the 35, but the real usefulness for me is having a 2nd '50 that I'll know I can use if I don't plan on heavy infinity work, but lots of close work. That's what my J3 is dedicated for right now.
I've owned the Nokton before, and it's a big big lens, next biggest 50 I've owned was the Noctilux 50/1. The J3 is about 1/2 the size, so it's my choice for modding/shimming/using.
I am not sure what you are trying to promote here...
I have said numerous times, that the simplest and easiest, non-destructive, easily reversible method to get the Nokton 50/1.5 to focus to 0.7m is with a shim/extension ring between the lens and camera/M-mount adapter as illustrated here...
...
With the correct shim thickness, any LTM 50mm can be made to focus to 0.7m with rangefinder coupling. The shim thickness will vary depending on the close focus distance built into the lens. The Nokton 50/1.5 requires a 0.9mm while the Rigid Heliar 50/2 requires a 1.1mm to get down to 0.7m. While I have been making my shims from aluminium, they can be made from an old membership, steel, old DVD/CD, etc.
While you have the shim/extension ring installed, you will not be able to focus the lens to infinity, the focus range will be limited from 0.7m to about 4m. Remove the shim/extension ring and the lens operates as normal.
Brian is the authority on J-3 construction and modification and I am sure he will be happy to contribute to a new thread about modifications that allow the J-3 to focus to 0.7m.
With some metal work, the focus range of the Nokton 50/1.5 be extended to 0.7m without the use of a shim/extension ring. The lens will focus continuously from infinity to 0.7m with a turn of the focus ring. The extra 0.2m was worth taking the time to permanently modify my Nokton 50/1.5.
Last edited:
P. Lynn Miller
Well-known
Ted,
The modification that you are proposing is that with a thinner shim, about .04mm, the Nokton 50/1.5 would focus from 'near' infinity to about 0.8m, thus making a more versatile solution than a 0.9mm shim which limits the usability of the lens from 4m to 0.7m. So nice compromise that would allow you to use the lens in 95% of situations without removing the shim. Good idea!
I am concentrating on the Nokton 50/1.5 and you are promoting the J-3. What we need to agree on is that this 'shim' solution will work on any LTM 50mm, Jupiter, Canon, Nikkor, Leitz, Voigtlander, etc.
The lightbulb moment for me was when Brian wrote this -
"The 50/1.5 Nokton is a screw mount lens. You can back it off a turn in the LTM to M-Mount adapter for closer focus. The actual optics and the RF Cam will move in unison, the actual focus will agree with what the RF indicates. You could make an LTM adapter with a "shim" on it to set the stand-off, and essentially get a hacked dual-range lens."
The common denominator the Nokton 50/1.5 and J-3 share is they are both 'screw-mount' 50's.
I chose the Nokton 50/1.5 because I wanted a modern, fast 50mm with multi-coating and etc. I particularly wanted to be able to modify the Nokton to focus to 0.7m. I wanted the Nokton to be a full range lens from infinity to 0.7m without shims, adapters, etc. So I was very happy to spend a few hours to permanently modify the Nokton.
You like the J-3 for all the right reasons and are happy to have the lens focus from near infinity to 0.8m. And have found a very quick and easy solution to modify the J-3.
The real important information to take away is that if you have a LTM 50mm, with use of a shim, you can make the lens focus closer. And the credit for this brilliant idea goes the Dr. Brian Sweeney.
It would be great if you would start a new thread about your modified J-3 with some pictures and information, would be useful for anyone else using a J-3.
The modification that you are proposing is that with a thinner shim, about .04mm, the Nokton 50/1.5 would focus from 'near' infinity to about 0.8m, thus making a more versatile solution than a 0.9mm shim which limits the usability of the lens from 4m to 0.7m. So nice compromise that would allow you to use the lens in 95% of situations without removing the shim. Good idea!
I am concentrating on the Nokton 50/1.5 and you are promoting the J-3. What we need to agree on is that this 'shim' solution will work on any LTM 50mm, Jupiter, Canon, Nikkor, Leitz, Voigtlander, etc.
The lightbulb moment for me was when Brian wrote this -
"The 50/1.5 Nokton is a screw mount lens. You can back it off a turn in the LTM to M-Mount adapter for closer focus. The actual optics and the RF Cam will move in unison, the actual focus will agree with what the RF indicates. You could make an LTM adapter with a "shim" on it to set the stand-off, and essentially get a hacked dual-range lens."
The common denominator the Nokton 50/1.5 and J-3 share is they are both 'screw-mount' 50's.
I chose the Nokton 50/1.5 because I wanted a modern, fast 50mm with multi-coating and etc. I particularly wanted to be able to modify the Nokton to focus to 0.7m. I wanted the Nokton to be a full range lens from infinity to 0.7m without shims, adapters, etc. So I was very happy to spend a few hours to permanently modify the Nokton.
You like the J-3 for all the right reasons and are happy to have the lens focus from near infinity to 0.8m. And have found a very quick and easy solution to modify the J-3.
The real important information to take away is that if you have a LTM 50mm, with use of a shim, you can make the lens focus closer. And the credit for this brilliant idea goes the Dr. Brian Sweeney.
It would be great if you would start a new thread about your modified J-3 with some pictures and information, would be useful for anyone else using a J-3.
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