First FSU lens

[olleorama]

Hi, got my first jupiter-8 yesterday, and have some questions regarding ergonomics. My lens seems to be somekind of newer export model. It has western letters and 'made in the USSR' on the barrel.

The focus scale runs 180 degrees and is extremely smooth, almost like it could refocus if you shook it. And also the aperture ring is not fixed, it rotates with the focus ring. Is this normal? Are all jupiters like this? It's a bit weird for me. And it's all very different from the '94 cron I usually use.

 

[Coldkennels]

That sounds exactly right. If the focusing ring is TOO loose, though, the lens could just need a bit of a regreasing. I've heard it's a simple job, but I've not done it myself.

 

[rbiemer]

Sounds normal for a late J-8 but, no, not all Jupiter 8s act as yours does. The early ones--called "white" or "chrome" but really just un colored aluminum--don't rotate the front of the lens as you focus. As far as I know no J-8s [except for the Kiev version] have click stops either.
Not anything to worry about, though. Shoot a roll of film with it and see how your results are.
Rob

 

[Sonnar Brian]

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

Kim Coxon has instructions for servicing the various types of Jupiter-8's.

If the focus is too loose, try a little white lithium grease on the helical. The optics module unscrews from the focus mount, set lens to infinity, you will see the stop screw to undo to take the helical apart. If you are new to this, you can just unscrew it part way to expose the helical, work some grease in. A little dab will do it.