Dez
Bodger Extraordinaire
Thanks for the info
Thanks for the info
Thanks very much! This is extremely helpful.
My lathe is rather small, and so can only grip the INSIDE of large objects like these, but hopefully I can get this done. The 4/3 adaptor is made of thick (~5mm) aluminum, so I should have some material to work with.
Cheers,
Dez
Thanks for the info
Thanks very much! This is extremely helpful.
My lathe is rather small, and so can only grip the INSIDE of large objects like these, but hopefully I can get this done. The 4/3 adaptor is made of thick (~5mm) aluminum, so I should have some material to work with.
Cheers,
Dez
Dez
Bodger Extraordinaire
Progress report
Progress report
So far so good. I scrounged a mount from a Kiev lens, and machined down the Nikon F to 4/3 adaptor. So now I have the correct spacing, and I am able to put an F lens on my S2. I was amazingly lucky. The whole thing ended up only .001 too thin, and the F mount ring is trivial to shim. :angel:
One more thing to do. The Nikkor 21 f4 has a very strange mount that makes use of a lug cast into Nikon camera bodies behind the lens mount, in order to align itself properly, very important in this case, as the protruding rear part of the lens fouls things if it rotates more than a few degrees. I am going to have to position the equivalent of that lug inside the adaptor. A project for tomorrow. Lots of other odd bits that I had not anticipated. I'll write this up when all is done for anyone who might want to play amateur machinist.
Cheers,
Dez
Progress report
So far so good. I scrounged a mount from a Kiev lens, and machined down the Nikon F to 4/3 adaptor. So now I have the correct spacing, and I am able to put an F lens on my S2. I was amazingly lucky. The whole thing ended up only .001 too thin, and the F mount ring is trivial to shim. :angel:
One more thing to do. The Nikkor 21 f4 has a very strange mount that makes use of a lug cast into Nikon camera bodies behind the lens mount, in order to align itself properly, very important in this case, as the protruding rear part of the lens fouls things if it rotates more than a few degrees. I am going to have to position the equivalent of that lug inside the adaptor. A project for tomorrow. Lots of other odd bits that I had not anticipated. I'll write this up when all is done for anyone who might want to play amateur machinist.
Cheers,
Dez
Mister E
Well-known
Can you just not remove that lug?
Dez
Bodger Extraordinaire
The magic lug
The magic lug
No, my problem is that I need to add it. This exists in F-mount film cameras, and may be specifically to fit the 21mm f4 lens. This is used to keep the body of the lens from rotating while you mount it with the strange breech-lock but F-compatible mount it uses. Without it, the lens will rotate and break things in the camera. I notice this lug does not exist in my Nikon DSLR's. Anyway, it should not be a big deal, but I had been trying to figure out how to do it without drilling a radial retaining hole, but now that I have given up on that nicety, it should be easy to finish.
I would like to get my hands on a manufactured one of these to see how they deal with some things. It looks like, for an adaptor that will work with the 21mm f4, that the lens mount catches for the F and S parts of the mount fall on top of each other. I have been forced to eliminate the catch on the F mount. I think I know how to deal with that, and if I make another one of these things, I will be able to retain it. I would be willing to bet that in the manufactured units the F lens is rotated counterclockwise relative to the camera body somewhat, so the focus index is not where it should be.
Cheers,
Dez
The magic lug
No, my problem is that I need to add it. This exists in F-mount film cameras, and may be specifically to fit the 21mm f4 lens. This is used to keep the body of the lens from rotating while you mount it with the strange breech-lock but F-compatible mount it uses. Without it, the lens will rotate and break things in the camera. I notice this lug does not exist in my Nikon DSLR's. Anyway, it should not be a big deal, but I had been trying to figure out how to do it without drilling a radial retaining hole, but now that I have given up on that nicety, it should be easy to finish.
I would like to get my hands on a manufactured one of these to see how they deal with some things. It looks like, for an adaptor that will work with the 21mm f4, that the lens mount catches for the F and S parts of the mount fall on top of each other. I have been forced to eliminate the catch on the F mount. I think I know how to deal with that, and if I make another one of these things, I will be able to retain it. I would be willing to bet that in the manufactured units the F lens is rotated counterclockwise relative to the camera body somewhat, so the focus index is not where it should be.
Cheers,
Dez
Last edited:
Mister E
Well-known
I think people that are using the CV F-S/C adapter with the Nikkor-O 2.1cm lens have removed that tab.
Dez
Bodger Extraordinaire
Success!!!
Success!!!
It's finished!
I made up the locating lug for the 21mm lens- a fiddly job, but not too difficult, and positioned it ever so carefully. The 21mm lens bayonets in properly, and is held in position properly.
The whole job cost me $45 for the Nikon to 4/3 adaptor, a mount scrounged from a Kiev lens, and two evenings wasted, but it's done, it's spot on dimensionally, and everything works properly.
Now, of course, I expect to find C-V ones in perfect shape selling for a song on ebay.
I took some pictures during the course of the project, and I will put that together into a set of instructions that I will post on the list, in case anyone else wants a shot at making one of these. It is actually easier than I had anticipated, and I got very lucky with the way some of the dimensions worked out. I was learning on the job, and did some unnecessary things in the process. I suspect that it all could have comfortably been done in one evening without the missteps.:bang:
And here it is! I'll need to run a roll of film through it to make sure, but I'm fairly certain I have the dimensions right.
Cheers,
Dez
Success!!!
It's finished!
I made up the locating lug for the 21mm lens- a fiddly job, but not too difficult, and positioned it ever so carefully. The 21mm lens bayonets in properly, and is held in position properly.
The whole job cost me $45 for the Nikon to 4/3 adaptor, a mount scrounged from a Kiev lens, and two evenings wasted, but it's done, it's spot on dimensionally, and everything works properly.
Now, of course, I expect to find C-V ones in perfect shape selling for a song on ebay.
I took some pictures during the course of the project, and I will put that together into a set of instructions that I will post on the list, in case anyone else wants a shot at making one of these. It is actually easier than I had anticipated, and I got very lucky with the way some of the dimensions worked out. I was learning on the job, and did some unnecessary things in the process. I suspect that it all could have comfortably been done in one evening without the missteps.:bang:
And here it is! I'll need to run a roll of film through it to make sure, but I'm fairly certain I have the dimensions right.
Cheers,
Dez
BillBingham2
Registered User
Very cool Dez. Please post pictures of the black magic along with drawings, numbers and such.
Thanks.
B2 (;->
Thanks.
B2 (;->
Mister E
Well-known
Very, very cool!
Looks great, Dez! So when do you start taking orders?
wes loder
Photographer/Historian
The Cosina adaptor gets around the lug problem by using a breechlock to mount the adaptor to the camera body. In that way the lug never rotates and will not hit the S mount. WES
Vickko
Veteran
I have a Cosina Nikon F to S adapter that I am considering selling.
Contact me with your best offer. It is in mint condition.
I sold my F 2.1cm lens, and don't have any other F lens, that I want to use on my Nikon RF bodies.
....Vick
Contact me with your best offer. It is in mint condition.
I sold my F 2.1cm lens, and don't have any other F lens, that I want to use on my Nikon RF bodies.
....Vick
Mister E
Well-known
I'm selling mine here: http://www.rangefinderforum.com/photopost-classifieds/showproduct.php?product=28292