Volna-3: some question

[ntx]

I finally received my copy of the Volna-3 80mm f/2.8 (Pentacon Six - have PK to P6 adapter) but I have some problem/question about it.
I noticed a small triangular lever on the side of the lens, it doesn't seems to move... what is its function?
I also have a problem with the focusing ring: it never reach the infinity symbol, stops a bit after 10 meters... is it easy to fix this problem? Mind that I have no experience in fixing lenses.

On the side the glass is perfect and the aperture ring moves nicely... at f/2.8 it's amazing! It's incredibly sharp and the bokeh is beautiful. I took some portrait of my daughter and I'm impressed by the results...

Bye
Jenner

[aoleg]

The lever is a DoF preview actuator. To test it, stop down the lens fo something other than wide open, say f/8. Turn it upside down and push the aperture control pin. The diafragm will open. Now, pull the triangle lever while still holding the pin, and the diaphragm will stop down again to allow you evaluate the depth of field at your chosen aperture. You won't use this lever when the lens is mounted on an adapter because P6 adapters don't usually press down the aperture control pin.

Focusing: sounds like a stuck helicoid. Can be anything, really. Bad news: you'll probably have to open the lens to service the helicoid. Good news: this lens is easy to work with. Large parts, big screws, simple construction. I opened mine for cleaning & lubricating, and everything was quite intuitive. The only thing that's important to know is that you should unscrew the three OUTER screws on the lens mount; leave the three inner (smaller) screws alone as they hold a spring you don't want (or need) to mess with. Of course, make sure you mark the entry position of the helicoid if you need to take it apart; otherwise, you'll spend some time figuring the correct entry point of the helicoid when assembling it back.

[ntx]

Thank you for your reply. I forgot to say that I cannot focus to infinity when I reach the maximum focusing distance in ring... is this be related with the helicoid?
What kind of lubricant I should use to if I want to let the focusing ring smoother?

Thank you again.

Bye
Jenner

[aoleg]

I use silicone-based lubricants. They provide excellent dampening, and will not evaporate or separate in high temperatures (mine is rated from -15 to +175C). Can be bought inexpensively in bike and auto repair shops; I paid $8 for a large tube. For most Russian lenses, Litnium-based lubricants won't usually work well; however, for some of the Japanese ones with finer threads (e.g. Takumars) they work great.