Jupiter-8 apperture scale and mark shift

[littlestevie]

Hi FSU fans,

I purchased a Jupiter-8 which needed to be shimmed to work properly with my Epson R-D1. Unfortunately the F2 and F22 no longer align with the aperture mark (all the scale is shifted). Is there a way to adjust the aperture ring to match again with the mark?

Best regards

Jef

 

[ImpMan71]

I regreased the focus helicoil on my J8 the other week & had the same problem.
It has a multipoint start on the thread & is possible to put in the wrong place. It took a while to sort out, but got there in the end. I would unscrew the lens block till it released, then continue turning it a bit further & then try & start in the thread in a different place.
Good luck.

 

[wolves3012]

There are 3 very tiny set-screws around the scale ring. Set the lens to the f/22 end of its range, loosen the screws, turn the ring to align the marks then re-tighten the set-screws. Be very careful that the screws don't fall out, it's easy to lose them!

 

[littlestevie]

Thank you for the answers!

ImpMan71,

I've unscrewed the lens block and continued turning when it was released while keeping a small pressure (similarly to when you want to screw the block on) , I only heard one click always at the same spot suggesting that on my lens there is only one start point (jupiter 8-1). I tried anyway but always ended up with the same scale shift.

Wolves3012,

I've read that these screws go into holes on the lens block thread, meaning that you can't screw them in another positions. Anyway I have to find a screw driver to deal with them, they are pretty small :-(

Thanks again

Jef

 

[Sonnar Brian]

You need a small screwdriver, I use a triple-zero. Undo the screws, line it up. You can use a fine tipped pick, or a hand-drill, to tap out a small hole to put them back in.

 

[wolves3012]

Wolves3012,

I've read that these screws go into holes on the lens block thread, meaning that you can't screw them in another positions. Anyway I have to find a screw driver to deal with them, they are pretty small :-(

Thanks again

Jef

Not true for the aperture-ring screws. They tend to have made small dents in their original positions, so it's hard to move them fractionally but if it's a bit further you'll be fine.

 

[Sonnar Brian]

This thread shows how a hand-drill can be used to tap out the new holes for the set screws. You want to get them deep enough so the screw heads do not protrude. This is more important on the J-3 than on the J-8, as the heads of the aperture ring screws will slide under for focus mount.

http://www.rangefinderforum.com/forums/showthread.php?t=51032

 

[littlestevie]

Brian,

I finally get a 1 mm screwdriver and did the job, I didn't need to tap out new holes, once screwed the screw did not protrude and the aperture ring was perfectly attached to the lens block.
I made some tests and that's an amazingly sharp lens once perfectly setup!

Jef

 

[Steve M.]

That's great that you got it sorted out. I've been surprised myself by how sharp a properly adjusted J8 lens is! I just bought a black one, and these 2 are from the first roll of fake Kodak B&W that was developed and scanned (badly) from my local Walgreens. The CL is not known for good focus close up and wide open, but the shot of Linda at f2 was pretty close. Can't wait to run some Tri -X through this lens.