J8 - Need Shims

[dave lackey]

Yikes, I have no idea what to do about shimming the J8 lens I received from Patrick...anyone have a source and recommendations?😱

 

[sig]

Kiev survival site: http://www3.telus.net/public/rpnchbck/checking lens working distance.html

Paper and alu foil seems to do it

 

[gb hill]

What year is your J8 Dave? By the 1st 2 #'s on the serial # mine is a 77. Someone may have some shims from an old J8 they might can send ya. My understanding is there are 3 variations of the J8 but I don't know if the shims are different sizes. good luck. That kiev survival site is good. you may need to go that route.

 

[Nomad Z]

Yes, tin foil or paper. If I was making some, I'd tape the sheet to a cutting mat and rig up some sort of compasses-type rotating cutter (cut smaller circle first). For my black mount J-8, sizes are 27mm inside diameter, 29.5mm outside. For the thin shims, it's probably okay to have a bigger outside diameter because there should be room for excess to fold down the side of optical module (away from the threaded part). The inside diameter of the Contax mount that's left over from my 1936 Sonnar is nearer 30mm.

When I shimmed my J-3 and Sonnar-into-J8, I used an old SLR focussing screen held over the film rails of my M2.

 

[ferider]

I cut them out of a coke can, Dave, with scissors.

 

[David Hughes]

Hi,

I know what curiosity did to the cat but still have to ask why do you think it needs shimming? Or did I miss something?

Regards, David

 

[gb hill]

Hi,

I know what curiosity did to the cat but still have to ask why do you think it needs shimming? Or did I miss something?

Regards, David

It was given to Dave but without any shims at all. So therefore it needs shimming.😀

 

[paulfish4570]

whatcha screwing that lens into?

 

[dave lackey]

whatcha screwing that lens into?

I have it on an adaptor for the M3. I was told it needed shimming. Greg showed me how to unscrew it and it appears to have a metal shim so, I don't know. I was expecting a second one much looser, this one doesn't budge.

I have it mounted, seems to focus on the patch just fine but will shoot a couple of test shots later on and it will be awhile before I finish the roll, and have it developed. I don't know if it needs shims or not. But I like the coke can idea! We'll see.😕

Anyone need a J8m with Contax mount?

 

[dave lackey]

I was the one that gave Dave the lens. It needs to be shimmed. I would suggest Dave that you optimize it for close focus à la Brian Sweeney way. It won't focus quite to infinity if you do this, but depth of field will more than correct the slight error there. I like Roland's idea of cutting a coke can and I would suggest it needs at least two or three coke cans thickness worth of shims. If I had a digital Leica I would have done it for you....

Yes, thanks, Patrick! Never tried anything like this and am looking forward to it...kinda like an arts and crafts project where I hope I don't cut myself!😛 But I will give it a go!

Nice lens btw and I am looking forward to what I can get from it.🙂

 

[dave lackey]

No problem Dave. Any questions just ask.

Thank you, sir.🙂

 

[David Hughes]

And thank you all. I wondered what camera it was going into, if it had been tested and so on. I just don't like the thought of people buying perfectly good J-8's etc and then having them modified for no apparent reason.

Regards, David

 

[Ron (Netherlands)]

All the J-8's I got in the past and the two I currently use, have been tack sharp on my Leica's, never needed any additional shims (neither my J-3's).