J8 help needed

[Pikapig]

Hopefully i posted in the right section.

I just receive my chrome J8 from ukraine and i realise that the lens can focus below 1m..is this normal?
I understand that the min focus distance for this lens should be 1m..

Im planning to use this lens on ny bessa and m2..how will i know if it can focus correctly? Is there a test that i can perform without shooting on negatives to see the results?

Lastly, what does shim means?

Thanks.

 

[wolves3012]

Hopefully i posted in the right section.

I just receive my chrome J8 from ukraine and i realise that the lens can focus below 1m..is this normal?
I understand that the min focus distance for this lens should be 1m..

Im planning to use this lens on ny bessa and m2..how will i know if it can focus correctly? Is there a test that i can perform without shooting on negatives to see the results?

Lastly, what does shim means?

Thanks.

Yes, you've posted in the right place. To answer your questions:
Yes, the J-8 does normally go slightly below 1m but not by much. If you can focus it well below 1m then the scale is possibly in need of adjustment. Does it focus properly to infinity and does the f-stop scale line up properly?

As for using it on non-FSU cameras, there's a small difference in focal length between FSU and Leica standards. This means that focus will not be totally accurate on Leica-standard bodies, this being worst when close up and wide open. Shimming refers to adjusting the position of the optics, by means of adding or removing shim washers within the lens, to get focus as close as possible. Brian Sweeney, on here, is the guru and can probably explain it better.

 

[Pikapig]

Hi

Thanks for the advice. Infinity seems to focus correctly..f stop seems proper as well..

Even at below 1m, focus seems possible on my camera..can a CLA get this to work on a leica?

Thanks

 

[Sonnar Brian]

A CLA can certainly optimize the J-8 for a Leica.

http://pentax-manuals.com/repairs.htm

A professional CLA can take care of it, fedka.com offers a CLA at a reasonable price.

http://fedka.com/catalog/index.php?cPath=48&osCsid=4f6683def35752c6a6dd0c72d8899da5

Instruct them that you want the lens optimized for a Leica.

This is not hard to do: the worst is realigning the aperture ring after shimming the optics module. The optics unscrew from the focus mount, you usually need to thicken the shim, and then have to undo three set screws in the aperture- realign - tap out some small holes - screw back in.

 

[Pikapig]

Just checked de lens, infinity seems ok but in my rf patch, i will see foregrd images appearing as well. Aperture ring seems to go beneath f2..

Thanks Brian for the advice n links..will check it out

 

[Pikapig]

Hi guys
After spending a whole day in office thinking about the lens, i finally brought it down to mr philip, decameraconsultant, for a decent check up!
I was thrilled when he said after testing on his M2, the lens is perfect in focusing..no need for any shimming or CLAd..

All along im being paranoid and i apologise on that..now im all ready to shoot some pictures!

Hopefully it turn out well
Once again thanks to everyone who helped out here!

 

[Pikapig]

Okay..my first roll is out...

the pics seems ok..

The scale might be wrong..it went near 0.8m for min focusing

flare control seems not tat good

Shot at ard 3m...

Overall im quite happy w this piece of glass i got..for a v nice price